diff --git a/moto/ec2/models.py b/moto/ec2/models.py
index 6e320c0ae..ad9ae3b1b 100644
--- a/moto/ec2/models.py
+++ b/moto/ec2/models.py
@@ -1516,6 +1516,19 @@ class AmiBackend(object):
 
         return True
 
+    def register_image(self, name=None, description=None):
+        ami_id = random_ami_id()
+        ami = Ami(
+            self,
+            ami_id,
+            instance=None,
+            source_ami=None,
+            name=name,
+            description=description,
+        )
+        self.amis[ami_id] = ami
+        return ami
+
     def remove_launch_permission(self, ami_id, user_ids=None, group=None):
         ami = self.describe_images(ami_ids=[ami_id])[0]
         self.validate_permission_targets(user_ids=user_ids, group=group)
diff --git a/moto/ec2/responses/amis.py b/moto/ec2/responses/amis.py
index 0e70182bb..178d583e0 100755
--- a/moto/ec2/responses/amis.py
+++ b/moto/ec2/responses/amis.py
@@ -73,8 +73,12 @@ class AmisResponse(BaseResponse):
             return MODIFY_IMAGE_ATTRIBUTE_RESPONSE
 
     def register_image(self):
+        name = self.querystring.get("Name")[0]
+        description = self._get_param("Description", if_none="")
         if self.is_not_dryrun("RegisterImage"):
-            raise NotImplementedError("AMIs.register_image is not yet implemented")
+            image = self.ec2_backend.register_image(name, description)
+            template = self.response_template(REGISTER_IMAGE_RESPONSE)
+            return template.render(image=image)
 
     def reset_image_attribute(self):
         if self.is_not_dryrun("ResetImageAttribute"):
@@ -190,3 +194,8 @@ MODIFY_IMAGE_ATTRIBUTE_RESPONSE = """
    <return>true</return>
 </ModifyImageAttributeResponse>
 """
+
+REGISTER_IMAGE_RESPONSE = """<RegisterImageResponse xmlns="http://ec2.amazonaws.com/doc/2013-10-15/">
+   <requestId>59dbff89-35bd-4eac-99ed-be587EXAMPLE</requestId>
+   <imageId>{{ image.id }}</imageId>
+</RegisterImageResponse>"""
diff --git a/tests/test_ec2/test_amis.py b/tests/test_ec2/test_amis.py
index 275b12905..220dd143c 100644
--- a/tests/test_ec2/test_amis.py
+++ b/tests/test_ec2/test_amis.py
@@ -773,6 +773,16 @@ def test_ami_describe_non_existent():
         img.load()
 
 
+@mock_ec2
+def test_ami_registration():
+    ec2 = boto3.client("ec2", region_name="us-east-1")
+    image_id = ec2.register_image(Name="test-register-image").get("ImageId", "")
+    images = ec2.describe_images(ImageIds=[image_id]).get("Images", [])
+    assert images[0]["Name"] == "test-register-image", "No image was registered."
+    assert images[0]["RootDeviceName"] == "/dev/sda1", "Wrong root device name."
+    assert images[0]["State"] == "available", "State should be available."
+
+
 @mock_ec2
 def test_ami_filter_wildcard():
     ec2_resource = boto3.resource("ec2", region_name="us-west-1")