diff --git a/homeassistant/components/transmission/config_flow.py b/homeassistant/components/transmission/config_flow.py
index c457306310d..8b43850623a 100644
--- a/homeassistant/components/transmission/config_flow.py
+++ b/homeassistant/components/transmission/config_flow.py
@@ -56,7 +56,10 @@ class TransmissionFlowHandler(config_entries.ConfigFlow, domain=DOMAIN):
         if user_input is not None:
 
             for entry in self.hass.config_entries.async_entries(DOMAIN):
-                if entry.data[CONF_HOST] == user_input[CONF_HOST]:
+                if (
+                    entry.data[CONF_HOST] == user_input[CONF_HOST]
+                    and entry.data[CONF_PORT] == user_input[CONF_PORT]
+                ):
                     return self.async_abort(reason="already_configured")
                 if entry.data[CONF_NAME] == user_input[CONF_NAME]:
                     errors[CONF_NAME] = "name_exists"
diff --git a/tests/components/transmission/test_config_flow.py b/tests/components/transmission/test_config_flow.py
index 6b9917d17f4..0820e71ae3b 100644
--- a/tests/components/transmission/test_config_flow.py
+++ b/tests/components/transmission/test_config_flow.py
@@ -204,13 +204,31 @@ async def test_host_already_configured(hass, api):
         options={CONF_SCAN_INTERVAL: DEFAULT_SCAN_INTERVAL},
     )
     entry.add_to_hass(hass)
-    result = await hass.config_entries.flow.async_init(
-        transmission.DOMAIN, context={"source": "user"}, data=MOCK_ENTRY
-    )
 
+    mock_entry_unique_name = MOCK_ENTRY.copy()
+    mock_entry_unique_name[CONF_NAME] = "Transmission 1"
+    result = await hass.config_entries.flow.async_init(
+        transmission.DOMAIN, context={"source": "user"}, data=mock_entry_unique_name
+    )
     assert result["type"] == "abort"
     assert result["reason"] == "already_configured"
 
+    mock_entry_unique_port = MOCK_ENTRY.copy()
+    mock_entry_unique_port[CONF_PORT] = 9092
+    mock_entry_unique_port[CONF_NAME] = "Transmission 2"
+    result = await hass.config_entries.flow.async_init(
+        transmission.DOMAIN, context={"source": "user"}, data=mock_entry_unique_port
+    )
+    assert result["type"] == data_entry_flow.RESULT_TYPE_CREATE_ENTRY
+
+    mock_entry_unique_host = MOCK_ENTRY.copy()
+    mock_entry_unique_host[CONF_HOST] = "192.168.1.101"
+    mock_entry_unique_host[CONF_NAME] = "Transmission 3"
+    result = await hass.config_entries.flow.async_init(
+        transmission.DOMAIN, context={"source": "user"}, data=mock_entry_unique_host
+    )
+    assert result["type"] == data_entry_flow.RESULT_TYPE_CREATE_ENTRY
+
 
 async def test_name_already_configured(hass, api):
     """Test name is already configured."""