diff --git a/libp2p/abc.py b/libp2p/abc.py
index a50a364d..dc941c43 100644
--- a/libp2p/abc.py
+++ b/libp2p/abc.py
@@ -2130,14 +2130,14 @@ class IPubsub(ServiceAPI):
         ...
 
     @abstractmethod
-    async def publish(self, topic_id: str, data: bytes) -> None:
+    async def publish(self, topic_id: str | list[str], data: bytes) -> None:
         """
-        Publish a message to a topic.
+        Publish a message to a topic or multiple topics.
 
         Parameters
         ----------
-        topic_id : str
-            The identifier of the topic.
+        topic_id : str | list[str]
+            The identifier of the topic (str) or topics (list[str]).
         data : bytes
             The data to publish.
 
diff --git a/libp2p/pubsub/pubsub.py b/libp2p/pubsub/pubsub.py
index 5f66f30a..8ba7d471 100644
--- a/libp2p/pubsub/pubsub.py
+++ b/libp2p/pubsub/pubsub.py
@@ -620,16 +620,22 @@ class Pubsub(Service, IPubsub):
                 logger.debug("Fail to message peer %s: stream closed", peer_id)
                 self._handle_dead_peer(peer_id)
 
-    async def publish(self, topic_id: str, data: bytes) -> None:
+    async def publish(self, topic_id: str | list[str], data: bytes) -> None:
         """
-        Publish data to a topic.
+        Publish data to a topic or multiple topics.
 
-        :param topic_id: topic which we are going to publish the data to
+        :param topic_id: topic (str) or topics (list[str]) to publish the data to
         :param data: data which we are publishing
         """
+        # Handle both single topic (str) and multiple topics (list[str])
+        if isinstance(topic_id, str):
+            topic_ids = [topic_id]
+        else:
+            topic_ids = topic_id
+
         msg = rpc_pb2.Message(
             data=data,
-            topicIDs=[topic_id],
+            topicIDs=topic_ids,
             # Origin is ourself.
             from_id=self.my_id.to_bytes(),
             seqno=self._next_seqno(),
diff --git a/newsfragments/685.feature.rst b/newsfragments/685.feature.rst
new file mode 100644
index 00000000..1ea15c49
--- /dev/null
+++ b/newsfragments/685.feature.rst
@@ -0,0 +1 @@
+Optimized pubsub publishing to send multiple topics in a single message instead of separate messages per topic.
diff --git a/tests/utils/pubsub/floodsub_integration_test_settings.py b/tests/utils/pubsub/floodsub_integration_test_settings.py
index ab895d71..4550a0f8 100644
--- a/tests/utils/pubsub/floodsub_integration_test_settings.py
+++ b/tests/utils/pubsub/floodsub_integration_test_settings.py
@@ -1,7 +1,3 @@
-# type: ignore
-# To add typing to this module, it's better to do it after refactoring test cases
-# into classes
-
 import pytest
 import trio
 
@@ -151,7 +147,7 @@ FLOODSUB_PROTOCOL_TEST_CASES = [
 ]
 
 floodsub_protocol_pytest_params = [
-    pytest.param(test_case, id=test_case["name"])
+    pytest.param(test_case, id=str(test_case["name"]))
     for test_case in FLOODSUB_PROTOCOL_TEST_CASES
 ]
 
@@ -241,10 +237,8 @@ async def perform_test_from_obj(obj, pubsub_factory) -> None:
             data = msg["data"]
             node_id = msg["node_id"]
 
-            # Publish message
-            # TODO: Should be single RPC package with several topics
-            for topic in topics:
-                await pubsub_map[node_id].publish(topic, data)
+            # Publish message - now uses single RPC package with several topics
+            await pubsub_map[node_id].publish(topics, data)
 
             # For each topic in topics, add (topic, node_id, data) tuple to
             # ordered test list