diff --git a/vsphere/resource_vsphere_virtual_disk.go b/vsphere/resource_vsphere_virtual_disk.go
index ca90f1181..dc50a52f5 100644
--- a/vsphere/resource_vsphere_virtual_disk.go
+++ b/vsphere/resource_vsphere_virtual_disk.go
@@ -38,6 +38,7 @@ func resourceVSphereVirtualDisk() *schema.Resource {
 	return &schema.Resource{
 		Create: resourceVSphereVirtualDiskCreate,
 		Read:   resourceVSphereVirtualDiskRead,
+		Update: resourceVSphereVirtualDiskUpdate,
 		Delete: resourceVSphereVirtualDiskDelete,
 		Importer: &schema.ResourceImporter{
 			State: resourceVSphereVirtualDiskImport,
@@ -48,7 +49,6 @@ func resourceVSphereVirtualDisk() *schema.Resource {
 			"size": {
 				Type:     schema.TypeInt,
 				Required: true,
-				ForceNew: true, // TODO Can this be optional (resize)?
 			},
 
 			// TODO:
@@ -334,6 +334,51 @@ func resourceVSphereVirtualDiskRead(d *schema.ResourceData, meta interface{}) er
 	return nil
 }
 
+func resourceVSphereVirtualDiskUpdate(d *schema.ResourceData, meta interface{}) error {
+	log.Printf("[INFO] Updating Virtual Disk")
+	client := meta.(*Client).vimClient
+
+	oldSize, newSize := d.GetChange("size")
+	if newSize.(int) < oldSize.(int) {
+		return fmt.Errorf("shrinking a virtual disk is not supported")
+	}
+
+	vDisk := virtualDisk{
+		size: d.Get("size").(int),
+	}
+
+	if v, ok := d.GetOk("vmdk_path"); ok {
+		vDisk.vmdkPath = v.(string)
+	}
+
+	if v, ok := d.GetOk("datastore"); ok {
+		vDisk.datastore = v.(string)
+	}
+
+	if v, ok := d.GetOk("datacenter"); ok {
+		vDisk.datacenter = v.(string)
+	}
+
+	finder := find.NewFinder(client.Client, true)
+
+	dc, err := getDatacenter(client, d.Get("datacenter").(string))
+	if err != nil {
+		return fmt.Errorf("error finding Datacenter: %s: %s", vDisk.datacenter, err)
+	}
+	finder = finder.SetDatacenter(dc)
+
+	ds, err := getDatastore(finder, vDisk.datastore)
+	if err != nil {
+		return fmt.Errorf("error finding Datastore: %s: %s", vDisk.datastore, err)
+	}
+
+	if err := extendHardDisk(client, vDisk.size, ds.Path(vDisk.vmdkPath), vDisk.datacenter); err != nil {
+		return err
+	}
+
+	return resourceVSphereVirtualDiskRead(d, meta)
+}
+
 func resourceVSphereVirtualDiskDelete(d *schema.ResourceData, meta interface{}) error {
 	client := meta.(*Client).vimClient
 
@@ -425,6 +470,29 @@ func createHardDisk(client *govmomi.Client, size int, diskPath string, diskType
 	return nil
 }
 
+func extendHardDisk(client *govmomi.Client, capacity int, diskPath string, dc string) error {
+	virtualDiskManager := object.NewVirtualDiskManager(client.Client)
+	datacenter, err := getDatacenter(client, dc)
+	if err != nil {
+		return err
+	}
+
+	capacityKb := int64(1024 * 1024 * capacity)
+	task, err := virtualDiskManager.ExtendVirtualDisk(context.TODO(), diskPath, datacenter, capacityKb, nil)
+	if err != nil {
+		return err
+	}
+
+	_, err = task.WaitForResultEx(context.TODO(), nil)
+	if err != nil {
+		log.Printf("[INFO] Failed to extend disk:  %v", err)
+		return err
+	}
+	log.Printf("[INFO] Extended disk.")
+
+	return nil
+}
+
 // Searches for the presence of a directory path.
 func searchForDirectory(client *govmomi.Client, datacenter string, datastore string, directoryPath string) error {
 	log.Printf("[DEBUG] Searching for Directory")
diff --git a/vsphere/resource_vsphere_virtual_disk_test.go b/vsphere/resource_vsphere_virtual_disk_test.go
index 94a632c2e..ccdcabead 100644
--- a/vsphere/resource_vsphere_virtual_disk_test.go
+++ b/vsphere/resource_vsphere_virtual_disk_test.go
@@ -32,7 +32,7 @@ func TestAccResourceVSphereVirtualDisk_basic(t *testing.T) {
 		CheckDestroy: testAccVSphereVirtualDiskExists("vsphere_virtual_disk.foo", false),
 		Steps: []resource.TestStep{
 			{
-				Config: testacccheckvspherevirtuadiskconfigBasic(rString),
+				Config: testacccheckvspherevirtualdiskconfigBasic(rString),
 				Check: resource.ComposeTestCheckFunc(
 					testAccVSphereVirtualDiskExists("vsphere_virtual_disk.foo", true),
 				),
@@ -41,6 +41,36 @@ func TestAccResourceVSphereVirtualDisk_basic(t *testing.T) {
 	})
 }
 
+func TestAccResourceVSphereVirtualDisk_extend(t *testing.T) {
+	rString := acctest.RandString(5)
+
+	resource.Test(t, resource.TestCase{
+		PreCheck: func() {
+			RunSweepers()
+			testAccPreCheck(t)
+			testAccResourceVSphereVirtualDiskPreCheck(t)
+		},
+		Providers:    testAccProviders,
+		CheckDestroy: testAccVSphereVirtualDiskExists("vsphere_virtual_disk.foo", false),
+		Steps: []resource.TestStep{
+			{
+				Config: testacccheckvspherevirtualdiskconfigBasic(rString),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttr(
+						"vsphere_virtual_disk.foo", "size", "1"),
+				),
+			},
+			{
+				Config: testacccheckvspherevirtualdiskconfigExtended(rString),
+				Check: resource.ComposeTestCheckFunc(
+					resource.TestCheckResourceAttr(
+						"vsphere_virtual_disk.foo", "size", "2"),
+				),
+			},
+		},
+	})
+}
+
 func TestAccResourceVSphereVirtualDisk_multi(t *testing.T) {
 	rString := acctest.RandString(5)
 
@@ -177,7 +207,7 @@ func testAccCheckVSphereVirtualDiskIsFileNotFoundError(err error) bool {
 	return false
 }
 
-func testacccheckvspherevirtuadiskconfigBasic(rName string) string {
+func testacccheckvspherevirtualdiskconfigBasic(rName string) string {
 	return fmt.Sprintf(`
 %s
 
@@ -199,6 +229,28 @@ resource "vsphere_virtual_disk" "foo" {
 	)
 }
 
+func testacccheckvspherevirtualdiskconfigExtended(rName string) string {
+	return fmt.Sprintf(`
+%s
+
+variable "rstring" {
+  default = "%s"
+}
+
+resource "vsphere_virtual_disk" "foo" {
+  size         = 2
+  vmdk_path    = "tfTestDisk-${var.rstring}.vmdk"
+  adapter_type = "lsiLogic"
+  type         = "thin"
+  datacenter   = "${data.vsphere_datacenter.rootdc1.name}"
+  datastore    = vsphere_nas_datastore.ds1.name
+}
+`,
+		testhelper.CombineConfigs(testhelper.ConfigDataRootDC1(), testhelper.ConfigDataRootHost1(), testhelper.ConfigDataRootHost2(), testhelper.ConfigResDS1()),
+		rName,
+	)
+}
+
 func testacccheckvspherevirtuadiskconfigMulti(rName string) string {
 	return fmt.Sprintf(`
 %s
diff --git a/website/docs/r/virtual_disk.html.markdown b/website/docs/r/virtual_disk.html.markdown
index 99c7f91b6..4f6006059 100644
--- a/website/docs/r/virtual_disk.html.markdown
+++ b/website/docs/r/virtual_disk.html.markdown
@@ -42,16 +42,18 @@ resource "vsphere_virtual_disk" "virtual_disk" {
 
 The following arguments are supported:
 
-~> **NOTE:** All fields in the `vsphere_virtual_disk` resource are currently
+~> **NOTE:** Some fields in the `vsphere_virtual_disk` resource are currently
 immutable and force a new resource if changed.
 
 * `vmdk_path` - (Required) The path, including filename, of the virtual disk to
   be created.  This needs to end in `.vmdk`.
 * `datastore` - (Required) The name of the datastore in which to create the
   disk.
-* `size` - (Required) Size of the disk (in GB).
+* `size` - (Required) Size of the disk (in GB). Decreasing the size of a disk is not possible.
+If a disk of a smaller size is required then the original has to be destroyed along with its data and a new one has to be
+created.
 * `datacenter` - (Optional) The name of the datacenter in which to create the
-  disk. Can be omitted when when ESXi or if there is only one datacenter in
+  disk. Can be omitted when ESXi or if there is only one datacenter in
   your infrastructure.
 * `type` - (Optional) The type of disk to create. Can be one of
   `eagerZeroedThick`, `lazy`, or `thin`. Default: `eagerZeroedThick`. For