diff --git a/README.md b/README.md
index 2406e0d..4c43022 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# go-plantuml 
+# go-plantuml
 [![Build Status](https://github.com/bykof/go-plantuml/actions/workflows/test.yml/badge.svg)](https://github.com/bykof/go-plantuml/actions/workflows/test.yml/badge.svg)
 [![Go Report Card](https://goreportcard.com/badge/github.com/bykof/go-plantuml)](https://goreportcard.com/report/github.com/bykof/go-plantuml)
 [![go-recipes](https://raw.githubusercontent.com/nikolaydubina/go-recipes/main/badge.svg?raw=true)](https://github.com/nikolaydubina/go-recipes)
@@ -42,6 +42,7 @@ Flags:
   -h, --help                  help for generate
   -o, --out string            the graphfile (default "graph.puml")
   -r, --recursive             traverse the given directories recursively
+  -x, --exclude               exclude file matching given regex expression, not used if using -f flag
 ```
 
 ## Example
@@ -83,10 +84,10 @@ type (
 
 func (address Address) FullAddress(withPostalCode bool) string {
 	return fmt.Sprintf(
-		"%s %s %d", 
-		PackageVariable, 
-		AnotherPackageVariable, 
-		StartingStreetNumber, 
+		"%s %s %d",
+		PackageVariable,
+		AnotherPackageVariable,
+		StartingStreetNumber,
 	)
 }
 
diff --git a/astParser/parser.go b/astParser/parser.go
index 3830109..276ab66 100644
--- a/astParser/parser.go
+++ b/astParser/parser.go
@@ -9,12 +9,18 @@ import (
 	"os"
 	"path/filepath"
 	"reflect"
+	"regexp"
 	"strings"
 
 	"github.com/bykof/go-plantuml/domain"
 )
 
-func ParseDirectory(directoryPath string, recursive bool) domain.Packages {
+func ParseDirectory(directoryPath string, opts ...ParserOptionFunc) domain.Packages {
+	options := &parserOptions{}
+	for _, opt := range opts {
+		opt(options)
+	}
+
 	var packages domain.Packages
 	files, err := os.ReadDir(directoryPath)
 	if err != nil {
@@ -32,14 +38,15 @@ func ParseDirectory(directoryPath string, recursive bool) domain.Packages {
 	for _, file := range files {
 		fullPath := filepath.Join(directoryPath, file.Name())
 		if !file.IsDir() {
-			if filepath.Ext(file.Name()) != ".go" || strings.Contains(file.Name(), "_test") {
+			if isExcluded(file.Name(), options.excludedFilesRegex) {
 				continue
 			}
+
 			parsedPackage := ParseFile(fullPath)
 			currentPackage = currentPackage.Add(parsedPackage)
 		} else {
-			if recursive {
-				packages = append(packages, ParseDirectory(fullPath, recursive)...)
+			if options.recursive {
+				packages = append(packages, ParseDirectory(fullPath, opts...)...)
 			}
 		}
 	}
@@ -51,6 +58,26 @@ func ParseDirectory(directoryPath string, recursive bool) domain.Packages {
 	return packages
 }
 
+func isExcluded(fileName string, regex *regexp.Regexp) bool {
+	if filepath.Ext(fileName) != ".go" {
+		return true
+	}
+
+	if strings.HasSuffix(fileName, "_test.go") {
+		return true
+	}
+
+	if regex == nil {
+		return false
+	}
+
+	if regex.Match([]byte(fileName)) {
+		return true
+	}
+
+	return false
+}
+
 func ParseFile(filePath string) domain.Package {
 	var domainPackage domain.Package
 
diff --git a/astParser/parser_option.go b/astParser/parser_option.go
new file mode 100644
index 0000000..3c9588a
--- /dev/null
+++ b/astParser/parser_option.go
@@ -0,0 +1,25 @@
+package astParser
+
+import (
+	"regexp"
+)
+
+type parserOptions struct {
+	recursive          bool
+	excludedFilesRegex *regexp.Regexp
+}
+
+type ParserOptionFunc func(*parserOptions)
+
+func WithRecursive() func(*parserOptions) {
+	return func(opt *parserOptions) {
+		opt.recursive = true
+	}
+}
+
+func WithFileExclusion(exclusionRegex string) func(*parserOptions) {
+	return func(opt *parserOptions) {
+		var re = regexp.MustCompile(exclusionRegex)
+		opt.excludedFilesRegex = re
+	}
+}
diff --git a/astParser/parser_option_test.go b/astParser/parser_option_test.go
new file mode 100644
index 0000000..27fbd71
--- /dev/null
+++ b/astParser/parser_option_test.go
@@ -0,0 +1,51 @@
+package astParser
+
+import (
+	"reflect"
+	"regexp"
+	"testing"
+)
+
+func TestWithRecursive(t *testing.T) {
+	tests := []struct {
+		name string
+		want *parserOptions
+	}{
+		{"positive", &parserOptions{recursive: true}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+
+			op := &parserOptions{}
+			opt := WithRecursive()
+			opt(op)
+			if !reflect.DeepEqual(op, tt.want) {
+				t.Errorf("WithRecursive() = %v, want %v", op, tt.want)
+			}
+		})
+	}
+}
+
+func TestWithFileExclusion(t *testing.T) {
+	type args struct {
+		exclusionRegex string
+	}
+	tests := []struct {
+		name string
+		args args
+		want *parserOptions
+	}{
+		{"positive", args{"^somefile.go$"}, &parserOptions{excludedFilesRegex: regexp.MustCompile("^somefile.go$")}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+
+			op := &parserOptions{}
+			opt := WithFileExclusion(tt.args.exclusionRegex)
+			opt(op)
+			if !reflect.DeepEqual(op, tt.want) {
+				t.Errorf("WithRecursive() = %v, want %v", op, tt.want)
+			}
+		})
+	}
+}
diff --git a/astParser/parser_test.go b/astParser/parser_test.go
index 198a7f9..aa9b21c 100644
--- a/astParser/parser_test.go
+++ b/astParser/parser_test.go
@@ -1 +1,32 @@
 package astParser
+
+import (
+	"regexp"
+	"testing"
+)
+
+func Test_isExcluded(t *testing.T) {
+	type args struct {
+		fileName string
+		regex    *regexp.Regexp
+	}
+	tests := []struct {
+		name string
+		args args
+		want bool
+	}{
+		{"positive_non_go_file_returns_true", args{"parser.js", nil}, true},
+		{"positive_go_test_file_returns_true", args{"parser_test.go", nil}, true},
+		{"positive_match_regex_returns_true", args{"parser_mock.go", regexp.MustCompile(`^.+_mock.go$`)}, true},
+		{"positive_match_regex_due_to_dot_returns_true", args{"parser_mock|tmp.go", regexp.MustCompile(`^.+_mock.tmp.go$`)}, true},
+		{"negative_go_file_no_regex_returns_false", args{"parser.go", nil}, false},
+		{"negative_go_file_did_not_match_regex_returns_false", args{"parser_mick.go", regexp.MustCompile(`^.+_mock.go$`)}, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := isExcluded(tt.args.fileName, tt.args.regex); got != tt.want {
+				t.Errorf("isExcluded() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
diff --git a/cmd/generate.go b/cmd/generate.go
index 0e041b1..88f6efa 100644
--- a/cmd/generate.go
+++ b/cmd/generate.go
@@ -15,6 +15,7 @@ var (
 	outPath     string
 	directories []string
 	files       []string
+	exclusion   string
 	recursive   bool
 	generateCmd = &cobra.Command{
 		Use:   "generate",
@@ -26,8 +27,17 @@ var (
 				packages = append(packages, astParser.ParseFile(file))
 			}
 
+			options := []astParser.ParserOptionFunc{}
+			if recursive {
+				options = append(options, astParser.WithRecursive())
+			}
+
+			if exclusion!=""{
+				options = append(options, astParser.WithFileExclusion(exclusion))
+			}
+
 			for _, directory := range directories {
-				packages = append(packages, astParser.ParseDirectory(directory, recursive)...)
+				packages = append(packages, astParser.ParseDirectory(directory, options...)...)
 			}
 
 			formattedPlantUML := formatter.FormatPlantUML(packages)
@@ -68,5 +78,12 @@ func init() {
 		false,
 		"traverse the given directories recursively",
 	)
+	generateCmd.Flags().StringVarP(
+		&exclusion,
+		"exclude",
+		"x",
+		"",
+		"exclude file matching given regex expression, not used if using -f flag",
+	)
 	rootCmd.AddCommand(generateCmd)
 }