diff --git a/demos/er.html b/demos/er.html
index 34e06acf85..662b8cbed3 100644
--- a/demos/er.html
+++ b/demos/er.html
@@ -71,6 +71,44 @@
     </pre>
     <hr />
 
+    <pre class="mermaid">
+      erDiagram
+        "HOSPITAL" {
+          int id PK
+          int doctor_id PK, FK
+          string address UK
+          string name
+          string phone_number
+          string fax_number
+        }
+      </pre
+    >
+    <hr />
+
+    <pre class="mermaid">
+      erDiagram
+        CAR ||--o{ NAMED-DRIVER : allows
+        CAR {
+          string registrationNumber PK
+          string make
+          string model
+          string[] parts
+        }
+        PERSON ||--o{ NAMED-DRIVER : is
+        PERSON {
+          string driversLicense PK "The license #"
+          string(99) firstName "Only 99 characters are allowed"
+          string lastName
+          string phone UK
+          int age
+        }
+        NAMED-DRIVER {
+          string carRegistrationNumber PK, FK
+          string driverLicence PK,FK
+        }
+        MANUFACTURER only one to zero or more CAR : makes
+    </pre>
+
     <script src="./mermaid.js"></script>
     <script type="module">
       mermaid.initialize({
diff --git a/docs/syntax/entityRelationshipDiagram.md b/docs/syntax/entityRelationshipDiagram.md
index 9837ad92db..9fa5fa5173 100644
--- a/docs/syntax/entityRelationshipDiagram.md
+++ b/docs/syntax/entityRelationshipDiagram.md
@@ -200,14 +200,13 @@ The `type` and `name` values must begin with an alphabetic character and may con
 
 #### Attribute Keys and Comments
 
-Attributes may also have a `key` or comment defined. Keys can be "PK", "FK" or "UK", for Primary Key, Foreign Key or Unique Key. And a `comment` is defined by double quotes at the end of an attribute. Comments themselves cannot have double-quote characters in them.
+Attributes may also have a `key` or comment defined. Keys can be `PK`, `FK` or `UK`, for Primary Key, Foreign Key or Unique Key. To specify multiple key constraints on a single attribute, separate them with a comma (e.g., `PK, FK`).. A `comment` is defined by double quotes at the end of an attribute. Comments themselves cannot have double-quote characters in them.
 
 ```mermaid-example
 erDiagram
     CAR ||--o{ NAMED-DRIVER : allows
     CAR {
-        string allowedDriver FK "The license of the allowed driver"
-        string registrationNumber UK
+        string registrationNumber PK
         string make
         string model
         string[] parts
@@ -217,17 +216,21 @@ erDiagram
         string driversLicense PK "The license #"
         string(99) firstName "Only 99 characters are allowed"
         string lastName
+        string phone UK
         int age
     }
-    MANUFACTURER only one to zero or more CAR
+    NAMED-DRIVER {
+        string carRegistrationNumber PK, FK
+        string driverLicence PK, FK
+    }
+    MANUFACTURER only one to zero or more CAR : makes
 ```
 
 ```mermaid
 erDiagram
     CAR ||--o{ NAMED-DRIVER : allows
     CAR {
-        string allowedDriver FK "The license of the allowed driver"
-        string registrationNumber UK
+        string registrationNumber PK
         string make
         string model
         string[] parts
@@ -237,9 +240,14 @@ erDiagram
         string driversLicense PK "The license #"
         string(99) firstName "Only 99 characters are allowed"
         string lastName
+        string phone UK
         int age
     }
-    MANUFACTURER only one to zero or more CAR
+    NAMED-DRIVER {
+        string carRegistrationNumber PK, FK
+        string driverLicence PK, FK
+    }
+    MANUFACTURER only one to zero or more CAR : makes
 ```
 
 ### Other Things
diff --git a/packages/mermaid/src/diagrams/er/erRenderer.js b/packages/mermaid/src/diagrams/er/erRenderer.js
index e3b12d087c..5dd5024bb9 100644
--- a/packages/mermaid/src/diagrams/er/erRenderer.js
+++ b/packages/mermaid/src/diagrams/er/erRenderer.js
@@ -59,7 +59,7 @@ const drawAttributes = (groupNode, entityTextNode, attributes) => {
 
   // Check to see if any of the attributes has a key or a comment
   attributes.forEach((item) => {
-    if (item.attributeKeyType !== undefined) {
+    if (item.attributeKeyTypeList !== undefined && item.attributeKeyTypeList.length > 0) {
       hasKeyType = true;
     }
 
@@ -112,6 +112,9 @@ const drawAttributes = (groupNode, entityTextNode, attributes) => {
     nodeHeight = Math.max(typeBBox.height, nameBBox.height);
 
     if (hasKeyType) {
+      const keyTypeNodeText =
+        item.attributeKeyTypeList !== undefined ? item.attributeKeyTypeList.join(',') : '';
+
       const keyTypeNode = groupNode
         .append('text')
         .classed('er entityLabel', true)
@@ -122,7 +125,7 @@ const drawAttributes = (groupNode, entityTextNode, attributes) => {
         .style('text-anchor', 'left')
         .style('font-family', getConfig().fontFamily)
         .style('font-size', attrFontSize + 'px')
-        .text(item.attributeKeyType || '');
+        .text(keyTypeNodeText);
 
       attributeNode.kn = keyTypeNode;
       const keyTypeBBox = keyTypeNode.node().getBBox();
diff --git a/packages/mermaid/src/diagrams/er/parser/erDiagram.jison b/packages/mermaid/src/diagrams/er/parser/erDiagram.jison
index ada176a8d4..15ca0c72f8 100644
--- a/packages/mermaid/src/diagrams/er/parser/erDiagram.jison
+++ b/packages/mermaid/src/diagrams/er/parser/erDiagram.jison
@@ -28,6 +28,7 @@ accDescr\s*"{"\s*                                { this.begin("acc_descr_multili
 \"[^"]*\"                       return 'WORD';
 "erDiagram"                     return 'ER_DIAGRAM';
 "{"                             { this.begin("block"); return 'BLOCK_START'; }
+<block>","                      return 'COMMA';
 <block>\s+                      /* skip whitespace in block */
 <block>\b((?:PK)|(?:FK)|(?:UK))\b      return 'ATTRIBUTE_KEY'
 <block>(.*?)[~](.*?)*[~]        return 'ATTRIBUTE_WORD';
@@ -131,11 +132,12 @@ attributes
 
 attribute
     : attributeType attributeName { $$ = { attributeType: $1, attributeName: $2 }; }
-    | attributeType attributeName attributeKeyType { $$ = { attributeType: $1, attributeName: $2, attributeKeyType: $3 }; }
+    | attributeType attributeName attributeKeyTypeList { $$ = { attributeType: $1, attributeName: $2, attributeKeyTypeList: $3 }; }
     | attributeType attributeName attributeComment { $$ = { attributeType: $1, attributeName: $2, attributeComment: $3 }; }
-    | attributeType attributeName attributeKeyType attributeComment { $$ = { attributeType: $1, attributeName: $2, attributeKeyType: $3, attributeComment: $4 }; }
+    | attributeType attributeName attributeKeyTypeList attributeComment { $$ = { attributeType: $1, attributeName: $2, attributeKeyTypeList: $3, attributeComment: $4 }; }
     ;
 
+
 attributeType
     : ATTRIBUTE_WORD { $$=$1; }
     ;
@@ -144,6 +146,11 @@ attributeName
     : ATTRIBUTE_WORD { $$=$1; }
     ;
 
+attributeKeyTypeList
+    : attributeKeyType { $$ = [$1]; }
+    | attributeKeyTypeList COMMA attributeKeyType { $1.push($3); $$ = $1; }
+    ;
+
 attributeKeyType
     : ATTRIBUTE_KEY { $$=$1; }
     ;
diff --git a/packages/mermaid/src/diagrams/er/parser/erDiagram.spec.js b/packages/mermaid/src/diagrams/er/parser/erDiagram.spec.js
index ba00c602e3..40ec28ada9 100644
--- a/packages/mermaid/src/diagrams/er/parser/erDiagram.spec.js
+++ b/packages/mermaid/src/diagrams/er/parser/erDiagram.spec.js
@@ -190,6 +190,28 @@ describe('when parsing ER diagram it...', function () {
     expect(entities[entity].attributes.length).toBe(4);
   });
 
+  it('should allow an entity with attributes that have many constraints and comments', function () {
+    const entity = 'CUSTOMER';
+    const attribute1 = 'int customer_number PK, FK "comment1"';
+    const attribute2 = 'datetime customer_status_start_datetime PK,UK, FK';
+    const attribute3 = 'datetime customer_status_end_datetime PK , UK "comment3"';
+    const attribute4 = 'string customer_firstname';
+    const attribute5 = 'string customer_lastname "comment5"';
+
+    erDiagram.parser.parse(
+      `erDiagram\n${entity} {\n${attribute1}\n${attribute2}\n${attribute3}\n${attribute4}\n${attribute5}\n}`
+    );
+    const entities = erDb.getEntities();
+    expect(entities[entity].attributes[0].attributeKeyTypeList).toEqual(['PK', 'FK']);
+    expect(entities[entity].attributes[0].attributeComment).toBe('comment1');
+    expect(entities[entity].attributes[1].attributeKeyTypeList).toEqual(['PK', 'UK', 'FK']);
+    expect(entities[entity].attributes[2].attributeKeyTypeList).toEqual(['PK', 'UK']);
+    expect(entities[entity].attributes[2].attributeComment).toBe('comment3');
+    expect(entities[entity].attributes[3].attributeKeyTypeList).toBeUndefined();
+    expect(entities[entity].attributes[4].attributeKeyTypeList).toBeUndefined();
+    expect(entities[entity].attributes[4].attributeComment).toBe('comment5');
+  });
+
   it('should allow an entity with attribute that has a generic type', function () {
     const entity = 'BOOK';
     const attribute1 = 'type~T~ type';
diff --git a/packages/mermaid/src/docs/syntax/entityRelationshipDiagram.md b/packages/mermaid/src/docs/syntax/entityRelationshipDiagram.md
index a670c6837e..7067a65d91 100644
--- a/packages/mermaid/src/docs/syntax/entityRelationshipDiagram.md
+++ b/packages/mermaid/src/docs/syntax/entityRelationshipDiagram.md
@@ -146,14 +146,13 @@ The `type` and `name` values must begin with an alphabetic character and may con
 
 #### Attribute Keys and Comments
 
-Attributes may also have a `key` or comment defined. Keys can be "PK", "FK" or "UK", for Primary Key, Foreign Key or Unique Key. And a `comment` is defined by double quotes at the end of an attribute. Comments themselves cannot have double-quote characters in them.
+Attributes may also have a `key` or comment defined. Keys can be `PK`, `FK` or `UK`, for Primary Key, Foreign Key or Unique Key. To specify multiple key constraints on a single attribute, separate them with a comma (e.g., `PK, FK`).. A `comment` is defined by double quotes at the end of an attribute. Comments themselves cannot have double-quote characters in them.
 
 ```mermaid-example
 erDiagram
     CAR ||--o{ NAMED-DRIVER : allows
     CAR {
-        string allowedDriver FK "The license of the allowed driver"
-        string registrationNumber UK
+        string registrationNumber PK
         string make
         string model
         string[] parts
@@ -163,9 +162,14 @@ erDiagram
         string driversLicense PK "The license #"
         string(99) firstName "Only 99 characters are allowed"
         string lastName
+        string phone UK
         int age
     }
-    MANUFACTURER only one to zero or more CAR
+    NAMED-DRIVER {
+        string carRegistrationNumber PK, FK
+        string driverLicence PK, FK
+    }
+    MANUFACTURER only one to zero or more CAR : makes
 ```
 
 ### Other Things