diff --git a/builder/hyperv/common/driver.go b/builder/hyperv/common/driver.go
index ba9ab5c4c..3e44b0ece 100644
--- a/builder/hyperv/common/driver.go
+++ b/builder/hyperv/common/driver.go
@@ -66,6 +66,8 @@ type Driver interface {
 
 	CreateVirtualMachine(string, string, string, string, int64, int64, string, uint) error
 
+	AddVirtualMachineHardDrive(string, string, string, int64, string) error
+
 	CloneVirtualMachine(string, string, string, bool, string, string, string, int64, string) error
 
 	DeleteVirtualMachine(string) error
diff --git a/builder/hyperv/common/driver_ps_4.go b/builder/hyperv/common/driver_ps_4.go
index c836137d2..c06294d49 100644
--- a/builder/hyperv/common/driver_ps_4.go
+++ b/builder/hyperv/common/driver_ps_4.go
@@ -170,6 +170,10 @@ func (d *HypervPS4Driver) CreateVirtualSwitch(switchName string, switchType stri
 	return hyperv.CreateVirtualSwitch(switchName, switchType)
 }
 
+func (d *HypervPS4Driver) AddVirtualMachineHardDrive(vmName string, vhdFile string, vhdName string, vhdSizeBytes int64, controllerType string) error {
+	return hyperv.AddVirtualMachineHardDiskDrive(vmName, vhdFile, vhdName, vhdSizeBytes, controllerType)
+}
+
 func (d *HypervPS4Driver) CreateVirtualMachine(vmName string, path string, harddrivePath string, vhdPath string, ram int64, diskSize int64, switchName string, generation uint) error {
 	return hyperv.CreateVirtualMachine(vmName, path, harddrivePath, vhdPath, ram, diskSize, switchName, generation)
 }
diff --git a/builder/hyperv/common/step_create_vm.go b/builder/hyperv/common/step_create_vm.go
index d88de5558..a244a9f5e 100644
--- a/builder/hyperv/common/step_create_vm.go
+++ b/builder/hyperv/common/step_create_vm.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"log"
 	"path/filepath"
+	"strconv"
 	"strings"
 
 	"github.com/hashicorp/packer/packer"
@@ -26,6 +27,7 @@ type StepCreateVM struct {
 	EnableDynamicMemory            bool
 	EnableSecureBoot               bool
 	EnableVirtualizationExtensions bool
+	AdditionalDiskSize             []uint
 }
 
 func (s *StepCreateVM) Run(state multistep.StateBag) multistep.StepAction {
@@ -108,6 +110,19 @@ func (s *StepCreateVM) Run(state multistep.StateBag) multistep.StepAction {
 		}
 	}
 
+	if len(s.AdditionalDiskSize) > 0 {
+		for index, size := range s.AdditionalDiskSize {
+			var diskSize = size * 1024 * 1024
+			err = driver.AddVirtualMachineHardDrive(s.VMName, vhdPath, s.VMName+"-"+strconv.Itoa(int(index))+".vhdx", int64(diskSize), "SCSI")
+			if err != nil {
+				err := fmt.Errorf("Error creating and attaching additional disk drive: %s", err)
+				state.Put("error", err)
+				ui.Error(err.Error())
+				return multistep.ActionHalt
+			}
+		}
+	}
+
 	// Set the final name in the state bag so others can use it
 	state.Put("vmName", s.VMName)
 
diff --git a/builder/hyperv/iso/builder.go b/builder/hyperv/iso/builder.go
index 2cd786a42..b3c1e1f61 100644
--- a/builder/hyperv/iso/builder.go
+++ b/builder/hyperv/iso/builder.go
@@ -90,6 +90,8 @@ type Config struct {
 
 	Communicator string `mapstructure:"communicator"`
 
+	AdditionalDiskSize []uint `mapstructure:"disk_additional_size"`
+
 	SkipCompaction bool `mapstructure:"skip_compaction"`
 
 	ctx interpolate.Context
@@ -163,6 +165,11 @@ func (b *Builder) Prepare(raws ...interface{}) ([]string, error) {
 		}
 	}
 
+	if len(b.config.AdditionalDiskSize) > 64 {
+		err = errors.New("VM's currently support a maximun of 64 additional SCSI attached disks.")
+		errs = packer.MultiErrorAppend(errs, err)
+	}
+
 	log.Println(fmt.Sprintf("Using switch %s", b.config.SwitchName))
 	log.Println(fmt.Sprintf("%s: %v", "SwitchName", b.config.SwitchName))
 
@@ -345,6 +352,7 @@ func (b *Builder) Run(ui packer.Ui, hook packer.Hook, cache packer.Cache) (packe
 			EnableDynamicMemory:            b.config.EnableDynamicMemory,
 			EnableSecureBoot:               b.config.EnableSecureBoot,
 			EnableVirtualizationExtensions: b.config.EnableVirtualizationExtensions,
+			AdditionalDiskSize:             b.config.AdditionalDiskSize,
 		},
 		&hypervcommon.StepEnableIntegrationService{},
 
diff --git a/builder/hyperv/iso/builder_test.go b/builder/hyperv/iso/builder_test.go
index 3fc17a8b7..73ae5591b 100644
--- a/builder/hyperv/iso/builder_test.go
+++ b/builder/hyperv/iso/builder_test.go
@@ -3,6 +3,7 @@ package iso
 import (
 	"fmt"
 	"reflect"
+	"strconv"
 	"testing"
 
 	"github.com/hashicorp/packer/packer"
@@ -18,6 +19,7 @@ func testConfig() map[string]interface{} {
 		"ram_size":                64,
 		"disk_size":               256,
 		"guest_additions_mode":    "none",
+		"disk_additional_size":    "50000,40000,30000",
 		packer.BuildNameConfigKey: "foo",
 	}
 }
@@ -391,6 +393,27 @@ func TestBuilderPrepare_SizeIsRequiredWhenNotUsingExistingHarddrive(t *testing.T
 	}
 }
 
+func TestBuilderPrepare_MaximumOfSixtyFourAdditionalDisks(t *testing.T) {
+	var b Builder
+	config := testConfig()
+
+	disks := make([]string, 65)
+	for i := range disks {
+		disks[i] = strconv.Itoa(i)
+	}
+	config["disk_additional_size"] = disks
+
+	b = Builder{}
+	warns, err := b.Prepare(config)
+	if len(warns) > 0 {
+		t.Fatalf("bad: %#v", warns)
+	}
+	if err == nil {
+		t.Errorf("should have error")
+	}
+
+}
+
 func TestBuilderPrepare_CommConfig(t *testing.T) {
 	// Test Winrm
 	{
@@ -447,4 +470,5 @@ func TestBuilderPrepare_CommConfig(t *testing.T) {
 			t.Errorf("bad host: %s", host)
 		}
 	}
+
 }
diff --git a/common/powershell/hyperv/hyperv.go b/common/powershell/hyperv/hyperv.go
index 0c649c450..d15ee0748 100644
--- a/common/powershell/hyperv/hyperv.go
+++ b/common/powershell/hyperv/hyperv.go
@@ -855,6 +855,19 @@ Get-VMNetworkAdapter -VMName $vmName | Connect-VMNetworkAdapter -SwitchName $swi
 	return err
 }
 
+func AddVirtualMachineHardDiskDrive(vmName string, vhdRoot string, vhdName string, vhdSizeBytes int64, controllerType string) error {
+
+	var script = `
+param([string]$vmName,[string]$vhdRoot, [string]$vhdName, [string]$vhdSizeInBytes, [string]$controllerType)
+$vhdPath = Join-Path -Path $vhdRoot -ChildPath $vhdName
+New-VHD $vhdPath -SizeBytes $vhdSizeInBytes
+Add-VMHardDiskDrive -VMName $vmName -path $vhdPath -controllerType $controllerType
+`
+	var ps powershell.PowerShellCmd
+	err := ps.Run(script, vmName, vhdRoot, vhdName, strconv.FormatInt(vhdSizeBytes, 10), controllerType)
+	return err
+}
+
 func UntagVirtualMachineNetworkAdapterVlan(vmName string, switchName string) error {
 
 	var script = `
diff --git a/website/source/docs/builders/hyperv-iso.html.md b/website/source/docs/builders/hyperv-iso.html.md
index be66cd0e2..b5b6a3826 100644
--- a/website/source/docs/builders/hyperv-iso.html.md
+++ b/website/source/docs/builders/hyperv-iso.html.md
@@ -88,6 +88,12 @@ can be configured for this builder.
 -   `cpu` (number) - The number of cpus the virtual machine should use. If this isn't specified,
     the default is 1 cpu.
 
+-   `disk_additional_size` (array of integers) - The size(s) of any additional
+    hard disks for the VM in megabytes. If this is not specified then the VM
+    will only contain a primary hard disk. Additional drives will be attached to the SCSI
+    interface only.  The builder uses expandable, not fixed-size virtual hard disks,
+    so the actual file representing the disk will not use the full size unless it is full.
+
 -   `disk_size` (number) - The size, in megabytes, of the hard disk to create
     for the VM. By default, this is 40 GB.