diff --git a/pkg/api/types.go b/pkg/api/types.go
index e6400b27733..2a5c550f937 100644
--- a/pkg/api/types.go
+++ b/pkg/api/types.go
@@ -17,9 +17,8 @@ limitations under the License.
 package api
 
 import (
-	"github.com/fsouza/go-dockerclient"
-
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+	"github.com/fsouza/go-dockerclient"
 )
 
 // Common string formats
@@ -270,7 +269,8 @@ type Service struct {
 	Selector                   map[string]string `json:"selector,omitempty" yaml:"selector,omitempty"`
 	CreateExternalLoadBalancer bool              `json:"createExternalLoadBalancer,omitempty" yaml:"createExternalLoadBalancer,omitempty"`
 
-	// Container port to connect to, either a name or a port number
+	// ContainerPort is the name of the port on the container to direct traffic to.
+	// Optional, if unspecified use the first port on the container.
 	ContainerPort util.IntOrString `json:"containerPort,omitempty" yaml:"containerPort,omitempty"`
 }
 
diff --git a/pkg/registry/endpoints.go b/pkg/registry/endpoints.go
index ab00a911c58..10a1db2be7b 100644
--- a/pkg/registry/endpoints.go
+++ b/pkg/registry/endpoints.go
@@ -17,11 +17,13 @@ limitations under the License.
 package registry
 
 import (
+	"fmt"
 	"net"
 	"strconv"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 	"github.com/golang/glog"
 )
 
@@ -37,6 +39,26 @@ type EndpointController struct {
 	podRegistry     PodRegistry
 }
 
+func findPort(manifest *api.ContainerManifest, portName util.IntOrString) (int, error) {
+	if ((portName.Kind == util.IntstrString && len(portName.StrVal) == 0) ||
+		(portName.Kind == util.IntstrInt && portName.IntVal == 0)) &&
+		len(manifest.Containers[0].Ports) > 0 {
+		return manifest.Containers[0].Ports[0].ContainerPort, nil
+	}
+	if portName.Kind == util.IntstrInt {
+		return portName.IntVal, nil
+	}
+	name := portName.StrVal
+	for _, container := range manifest.Containers {
+		for _, port := range container.Ports {
+			if port.Name == name {
+				return port.ContainerPort, nil
+			}
+		}
+	}
+	return -1, fmt.Errorf("no suitable port for manifest: %s", manifest.ID)
+}
+
 func (e *EndpointController) SyncServiceEndpoints() error {
 	services, err := e.serviceRegistry.ListServices()
 	if err != nil {
@@ -52,11 +74,12 @@ func (e *EndpointController) SyncServiceEndpoints() error {
 		}
 		endpoints := make([]string, len(pods))
 		for ix, pod := range pods {
-			// TODO: Use port names in the service object, don't just use port #0
-			endpoints[ix] = net.JoinHostPort(
-				pod.CurrentState.Host,
-				strconv.Itoa(pod.DesiredState.Manifest.Containers[0].Ports[0].HostPort),
-			)
+			port, err := findPort(&pod.DesiredState.Manifest, service.ContainerPort)
+			if err != nil {
+				glog.Errorf("Failed to find port for service: %v, %v", service, err)
+				continue
+			}
+			endpoints[ix] = net.JoinHostPort(pod.CurrentState.PodIP, strconv.Itoa(port))
 		}
 		err = e.serviceRegistry.UpdateEndpoints(api.Endpoints{
 			Name:      service.ID,
diff --git a/pkg/registry/endpoints_test.go b/pkg/registry/endpoints_test.go
index 71250d04c69..8581bbae701 100644
--- a/pkg/registry/endpoints_test.go
+++ b/pkg/registry/endpoints_test.go
@@ -21,8 +21,62 @@ import (
 	"testing"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
 )
 
+func TestFindPort(t *testing.T) {
+	manifest := api.ContainerManifest{
+		Containers: []api.Container{
+			{
+				Ports: []api.Port{
+					{
+						Name:          "foo",
+						ContainerPort: 8080,
+						HostPort:      9090,
+					},
+					{
+						Name:          "bar",
+						ContainerPort: 8000,
+						HostPort:      9000,
+					},
+				},
+			},
+		},
+	}
+	port, err := findPort(&manifest, util.IntOrString{Kind: util.IntstrString, StrVal: "foo"})
+	expectNoError(t, err)
+	if port != 8080 {
+		t.Errorf("Expected 8080, Got %d", port)
+	}
+	port, err = findPort(&manifest, util.IntOrString{Kind: util.IntstrString, StrVal: "bar"})
+	expectNoError(t, err)
+	if port != 8000 {
+		t.Errorf("Expected 8000, Got %d", port)
+	}
+	port, err = findPort(&manifest, util.IntOrString{Kind: util.IntstrInt, IntVal: 8000})
+	if port != 8000 {
+		t.Errorf("Expected 8000, Got %d", port)
+	}
+	port, err = findPort(&manifest, util.IntOrString{Kind: util.IntstrInt, IntVal: 7000})
+	if port != 7000 {
+		t.Errorf("Expected 7000, Got %d", port)
+	}
+	port, err = findPort(&manifest, util.IntOrString{Kind: util.IntstrString, StrVal: "baz"})
+	if err == nil {
+		t.Error("unexpected non-error")
+	}
+	port, err = findPort(&manifest, util.IntOrString{Kind: util.IntstrString, StrVal: ""})
+	expectNoError(t, err)
+	if port != 8080 {
+		t.Errorf("Expected 8080, Got %d", port)
+	}
+	port, err = findPort(&manifest, util.IntOrString{})
+	expectNoError(t, err)
+	if port != 8080 {
+		t.Errorf("Expected 8080, Got %d", port)
+	}
+}
+
 func TestSyncEndpointsEmpty(t *testing.T) {
 	serviceRegistry := MockServiceRegistry{}
 	podRegistry := MockPodRegistry{}