diff --git a/modules/openapi-generator/src/main/resources/powershell/api_client.mustache b/modules/openapi-generator/src/main/resources/powershell/api_client.mustache
index 5c364247594..2435b7b0ced 100644
--- a/modules/openapi-generator/src/main/resources/powershell/api_client.mustache
+++ b/modules/openapi-generator/src/main/resources/powershell/api_client.mustache
@@ -56,9 +56,15 @@ function Invoke-{{{apiNamePrefix}}}ApiClient {
         $HeaderParameters['Accept'] = $Accept
     }
 
+    [string]$MultiPartBoundary = $null
     $ContentType= SelectHeaders -Headers $ContentTypes
     if ($ContentType) {
         $HeaderParameters['Content-Type'] = $ContentType
+        if ($ContentType -eq 'multipart/form-data') {
+            [string]$MultiPartBoundary = [System.Guid]::NewGuid()
+            $MultiPartBoundary = "---------------------------$MultiPartBoundary"
+            $HeaderParameters['Content-Type'] = "$ContentType; boundary=$MultiPartBoundary"
+        }
     }
 
     # add default headers if any
@@ -66,7 +72,6 @@ function Invoke-{{{apiNamePrefix}}}ApiClient {
         $HeaderParameters[$header.Name] = $header.Value
     }
 
-
     # construct URL query string
     $HttpValues = [System.Web.HttpUtility]::ParseQueryString([String]::Empty)
     foreach ($Parameter in $QueryParameters.GetEnumerator()) {
@@ -84,9 +89,34 @@ function Invoke-{{{apiNamePrefix}}}ApiClient {
 
     # include form parameters in the request body
     if ($FormParameters -and $FormParameters.Count -gt 0) {
-        $RequestBody = $FormParameters
+        if (![string]::IsNullOrEmpty($MultiPartBoundary)) {
+            $RequestBody = ""
+            $LF = "`r`n"
+            $FormParameters.Keys | ForEach-Object {
+                $value = $FormParameters[$_]
+                $isFile = $value.GetType().FullName -eq "System.IO.FileInfo"
+
+                $RequestBody += "--$MultiPartBoundary$LF"
+                $RequestBody += "Content-Disposition: form-data; name=`"$_`""
+                if ($isFile) {
+                    $fileName = $value.Name
+                    $RequestBody += "; filename=`"$fileName`"$LF"
+                    $RequestBody += "Content-Type: application/octet-stream$LF$LF"
+                    $RequestBody += Get-Content -Path $value.FullName
+                } else {
+                    $RequestBody += "$LF$LF"
+                    $RequestBody += ([string]$value)
+                }
+                $RequestBody += "$LF--$MultiPartBoundary"
+            }
+            $RequestBody += "--"
+        } else {
+            $RequestBody = $FormParameters
+        }
     }
 
+
+
     if ($Body -or $IsBodyNullable) {
         $RequestBody = $Body
         if ([string]::IsNullOrEmpty($RequestBody) -and $IsBodyNullable -eq $true) {
diff --git a/samples/client/petstore/powershell/src/PSPetstore/PSPetstore.psd1 b/samples/client/petstore/powershell/src/PSPetstore/PSPetstore.psd1
index 6329693a91f..2860418807d 100644
--- a/samples/client/petstore/powershell/src/PSPetstore/PSPetstore.psd1
+++ b/samples/client/petstore/powershell/src/PSPetstore/PSPetstore.psd1
@@ -3,7 +3,7 @@
 #
 # Generated by: OpenAPI Generator Team
 #
-# Generated on: 30-11-2020
+# Generated on: 10/30/2021
 #
 
 @{
@@ -45,7 +45,7 @@ PowerShellVersion = '5.0'
 # DotNetFrameworkVersion = ''
 
 # Minimum version of the common language runtime (CLR) required by this module. This prerequisite is valid for the PowerShell Desktop edition only.
-# CLRVersion = ''
+# ClrVersion = ''
 
 # Processor architecture (None, X86, Amd64) required by this module
 # ProcessorArchitecture = ''
@@ -128,6 +128,15 @@ PrivateData = @{
         # ReleaseNotes of this module
         ReleaseNotes = 'This is a sample project'
 
+        # Prerelease string of this module
+        # Prerelease = ''
+
+        # Flag to indicate whether the module requires explicit user acceptance for install/update/save
+        # RequireLicenseAcceptance = $false
+
+        # External dependent modules of this module
+        # ExternalModuleDependencies = @()
+
     } # End of PSData hashtable
 
 } # End of PrivateData hashtable
diff --git a/samples/client/petstore/powershell/src/PSPetstore/Private/PSApiClient.ps1 b/samples/client/petstore/powershell/src/PSPetstore/Private/PSApiClient.ps1
index aacf6f6d0d1..11745f18614 100644
--- a/samples/client/petstore/powershell/src/PSPetstore/Private/PSApiClient.ps1
+++ b/samples/client/petstore/powershell/src/PSPetstore/Private/PSApiClient.ps1
@@ -62,9 +62,15 @@ function Invoke-PSApiClient {
         $HeaderParameters['Accept'] = $Accept
     }
 
+    [string]$MultiPartBoundary = $null
     $ContentType= SelectHeaders -Headers $ContentTypes
     if ($ContentType) {
         $HeaderParameters['Content-Type'] = $ContentType
+        if ($ContentType -eq 'multipart/form-data') {
+            [string]$MultiPartBoundary = [System.Guid]::NewGuid()
+            $MultiPartBoundary = "---------------------------$MultiPartBoundary"
+            $HeaderParameters['Content-Type'] = "$ContentType; boundary=$MultiPartBoundary"
+        }
     }
 
     # add default headers if any
@@ -72,7 +78,6 @@ function Invoke-PSApiClient {
         $HeaderParameters[$header.Name] = $header.Value
     }
 
-
     # construct URL query string
     $HttpValues = [System.Web.HttpUtility]::ParseQueryString([String]::Empty)
     foreach ($Parameter in $QueryParameters.GetEnumerator()) {
@@ -90,9 +95,34 @@ function Invoke-PSApiClient {
 
     # include form parameters in the request body
     if ($FormParameters -and $FormParameters.Count -gt 0) {
-        $RequestBody = $FormParameters
+        if (![string]::IsNullOrEmpty($MultiPartBoundary)) {
+            $RequestBody = ""
+            $LF = "`r`n"
+            $FormParameters.Keys | ForEach-Object {
+                $value = $FormParameters[$_]
+                $isFile = $value.GetType().FullName -eq "System.IO.FileInfo"
+
+                $RequestBody += "--$MultiPartBoundary$LF"
+                $RequestBody += "Content-Disposition: form-data; name=`"$_`""
+                if ($isFile) {
+                    $fileName = $value.Name
+                    $RequestBody += "; filename=`"$fileName`"$LF"
+                    $RequestBody += "Content-Type: application/octet-stream$LF$LF"
+                    $RequestBody += Get-Content -Path $value.FullName
+                } else {
+                    $RequestBody += "$LF$LF"
+                    $RequestBody += ([string]$value)
+                }
+                $RequestBody += "$LF--$MultiPartBoundary"
+            }
+            $RequestBody += "--"
+        } else {
+            $RequestBody = $FormParameters
+        }
     }
 
+
+
     if ($Body -or $IsBodyNullable) {
         $RequestBody = $Body
         if ([string]::IsNullOrEmpty($RequestBody) -and $IsBodyNullable -eq $true) {