diff --git a/cmd/minikube/cmd/flags.go b/cmd/minikube/cmd/flags.go
new file mode 100644
index 0000000000000000000000000000000000000000..332bdb0c7b6a56387407e7ebfaab902e12b567b8
--- /dev/null
+++ b/cmd/minikube/cmd/flags.go
@@ -0,0 +1,40 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package cmd
+
+import "github.com/docker/go-units"
+
+// unitValue represents an int64 flag specified with units as a string.
+type unitValue int64
+
+func newUnitValue(v int64) *unitValue {
+	return (*unitValue)(&v)
+}
+
+func (u *unitValue) Set(s string) error {
+	v, err := units.FromHumanSize(s)
+	*u = unitValue(v)
+	return err
+}
+
+func (u *unitValue) Type() string {
+	return "unit"
+}
+
+func (u *unitValue) String() string {
+	return units.HumanSize(float64(*u))
+}
diff --git a/cmd/minikube/cmd/start.go b/cmd/minikube/cmd/start.go
index 067bb6830ac7c4a25548c357f1875fa24b1e68f2..a6e12c732c6d8f218a1977143c71e41ac9830ccd 100644
--- a/cmd/minikube/cmd/start.go
+++ b/cmd/minikube/cmd/start.go
@@ -22,6 +22,7 @@ import (
 	"strconv"
 	"strings"
 
+	"github.com/docker/go-units"
 	"github.com/docker/machine/libmachine"
 	"github.com/docker/machine/libmachine/host"
 	"github.com/golang/glog"
@@ -37,6 +38,7 @@ var (
 	minikubeISO string
 	memory      int
 	cpus        int
+	disk        = newUnitValue(20 * units.GB)
 	vmDriver    string
 )
 
@@ -58,9 +60,12 @@ func runStart(cmd *cobra.Command, args []string) {
 		MinikubeISO: minikubeISO,
 		Memory:      memory,
 		CPUs:        cpus,
+		DiskSize:    int(*disk / units.MB),
 		VMDriver:    vmDriver,
 	}
 
+	fmt.Println(config.DiskSize)
+
 	var host *host.Host
 	start := func() (err error) {
 		host, err = cluster.StartHost(api, config)
@@ -154,5 +159,7 @@ func init() {
 	startCmd.Flags().StringVarP(&vmDriver, "vm-driver", "", constants.DefaultVMDriver, fmt.Sprintf("VM driver is one of: %v", constants.SupportedVMDrivers))
 	startCmd.Flags().IntVarP(&memory, "memory", "", constants.DefaultMemory, "Amount of RAM allocated to the minikube VM")
 	startCmd.Flags().IntVarP(&cpus, "cpus", "", constants.DefaultCPUS, "Number of CPUs allocated to the minikube VM")
+	diskFlag := startCmd.Flags().VarPF(disk, "disk-size", "", "Disk size allocated to the minikube VM (format: <number>[<unit>], where unit = b, k, m or g)")
+	diskFlag.DefValue = constants.DefaultDiskSize
 	RootCmd.AddCommand(startCmd)
 }
diff --git a/docs/minikube_start.md b/docs/minikube_start.md
index b6854d80338f39565a49f0ffd788b437a57f7786..35df617d87f20c91e7cbb15474d5cd6b53e45b63 100644
--- a/docs/minikube_start.md
+++ b/docs/minikube_start.md
@@ -16,6 +16,7 @@ minikube start
 
 ```
       --cpus=1: Number of CPUs allocated to the minikube VM
+      --disk-size=20g: Disk size allocated to the minikube VM (format: <number>[<unit>], where unit = b, k, m or g)
       --iso-url="https://storage.googleapis.com/minikube/minikube-0.5.iso": Location of the minikube iso
       --memory=1024: Amount of RAM allocated to the minikube VM
       --vm-driver="virtualbox": VM driver is one of: [virtualbox vmwarefusion kvm xhyve]
diff --git a/pkg/minikube/cluster/cluster.go b/pkg/minikube/cluster/cluster.go
index dcd39261d68ea721f2eac279e9ba67f72552a10c..c275144983f3639f5ef52033573e1d0292039ced 100644
--- a/pkg/minikube/cluster/cluster.go
+++ b/pkg/minikube/cluster/cluster.go
@@ -161,6 +161,7 @@ type MachineConfig struct {
 	MinikubeISO string
 	Memory      int
 	CPUs        int
+	DiskSize    int
 	VMDriver    string
 }
 
@@ -277,6 +278,7 @@ func createHost(api libmachine.API, config MachineConfig) (*host.Host, error) {
 		d.Boot2DockerURL = config.MinikubeISO
 		d.Memory = config.Memory
 		d.CPU = config.CPUs
+		d.DiskSize = int(config.DiskSize)
 		driver = d
 	case "vmwarefusion":
 		driver = createVMwareFusionHost(config)
diff --git a/pkg/minikube/cluster/cluster_darwin.go b/pkg/minikube/cluster/cluster_darwin.go
index 4bde535f0e09fb7056cc72975964ebfa5f48ebcb..b0a742de4573afbb048a2a5f374c737704692562 100644
--- a/pkg/minikube/cluster/cluster_darwin.go
+++ b/pkg/minikube/cluster/cluster_darwin.go
@@ -61,6 +61,6 @@ func createXhyveHost(config MachineConfig) *xhyveDriver {
 		CPU:            config.CPUs,
 		Boot2DockerURL: config.MinikubeISO,
 		BootCmd:        "loglevel=3 user=docker console=ttyS0 console=tty0 noembed nomodeset norestore waitusb=10 base host=boot2docker",
-		DiskSize:       20000,
+		DiskSize:       int64(config.DiskSize),
 	}
 }
diff --git a/pkg/minikube/cluster/cluster_linux.go b/pkg/minikube/cluster/cluster_linux.go
index bd51a97a2a52e2082f49484bf93d94b874e9f032..a9e3712966d7bfeef444d3fbebf3f4f6106505ce 100644
--- a/pkg/minikube/cluster/cluster_linux.go
+++ b/pkg/minikube/cluster/cluster_linux.go
@@ -50,7 +50,7 @@ func createKVMHost(config MachineConfig) *kvmDriver {
 		Network:        "default",
 		PrivateNetwork: "docker-machines",
 		Boot2DockerURL: config.MinikubeISO,
-		DiskSize:       20000,
+		DiskSize:       config.DiskSize,
 		DiskPath:       filepath.Join(constants.Minipath, "machines", constants.MachineName, fmt.Sprintf("%s.img", constants.MachineName)),
 		ISO:            filepath.Join(constants.Minipath, "machines", constants.MachineName, "boot2docker.iso"),
 		CacheMode:      "default",
diff --git a/pkg/minikube/constants/constants.go b/pkg/minikube/constants/constants.go
index f2ef27347442493a5e58d33ee0f5834d5b3c881d..59994fbad85b0d8fecd727bc7bda7751d98cef9e 100644
--- a/pkg/minikube/constants/constants.go
+++ b/pkg/minikube/constants/constants.go
@@ -61,6 +61,7 @@ const (
 	DefaultIsoUrl   = "https://storage.googleapis.com/minikube/minikube-0.5.iso"
 	DefaultMemory   = 1024
 	DefaultCPUS     = 1
+	DefaultDiskSize = "20g"
 	DefaultVMDriver = "virtualbox"
 )