diff --git a/src/google/adk/sessions/base_session_service.py b/src/google/adk/sessions/base_session_service.py
index 98072b0..82dcd99 100644
--- a/src/google/adk/sessions/base_session_service.py
+++ b/src/google/adk/sessions/base_session_service.py
@@ -40,13 +40,6 @@ class ListSessionsResponse(BaseModel):
   sessions: list[Session] = Field(default_factory=list)
 
 
-class ListEventsResponse(BaseModel):
-  """The response of listing events in a session."""
-
-  events: list[Event] = Field(default_factory=list)
-  next_page_token: Optional[str] = None
-
-
 class BaseSessionService(abc.ABC):
   """Base class for session services.
 
@@ -102,17 +95,6 @@ class BaseSessionService(abc.ABC):
     """Deletes a session."""
     pass
 
-  @abc.abstractmethod
-  def list_events(
-      self,
-      *,
-      app_name: str,
-      user_id: str,
-      session_id: str,
-  ) -> ListEventsResponse:
-    """Lists events in a session."""
-    pass
-
   def close_session(self, *, session: Session):
     """Closes a session."""
     # TODO: determine whether we want to finalize the session here.
diff --git a/src/google/adk/sessions/database_session_service.py b/src/google/adk/sessions/database_session_service.py
index 181a279..f9d73ae 100644
--- a/src/google/adk/sessions/database_session_service.py
+++ b/src/google/adk/sessions/database_session_service.py
@@ -49,7 +49,6 @@ from ..events.event import Event
 from . import _session_util
 from .base_session_service import BaseSessionService
 from .base_session_service import GetSessionConfig
-from .base_session_service import ListEventsResponse
 from .base_session_service import ListSessionsResponse
 from .session import Session
 from .state import State
@@ -556,17 +555,6 @@ class DatabaseSessionService(BaseSessionService):
     super().append_event(session=session, event=event)
     return event
 
-  @override
-  def list_events(
-      self,
-      *,
-      app_name: str,
-      user_id: str,
-      session_id: str,
-  ) -> ListEventsResponse:
-    raise NotImplementedError()
-
-
 def convert_event(event: StorageEvent) -> Event:
   """Converts a storage event to an event."""
   return Event(
diff --git a/src/google/adk/sessions/in_memory_session_service.py b/src/google/adk/sessions/in_memory_session_service.py
index f3a9d42..0d79420 100644
--- a/src/google/adk/sessions/in_memory_session_service.py
+++ b/src/google/adk/sessions/in_memory_session_service.py
@@ -24,7 +24,6 @@ from typing_extensions import override
 from ..events.event import Event
 from .base_session_service import BaseSessionService
 from .base_session_service import GetSessionConfig
-from .base_session_service import ListEventsResponse
 from .base_session_service import ListSessionsResponse
 from .session import Session
 from .state import State
@@ -292,13 +291,3 @@ class InMemorySessionService(BaseSessionService):
     storage_session.last_update_time = event.timestamp
 
     return event
-
-  @override
-  def list_events(
-      self,
-      *,
-      app_name: str,
-      user_id: str,
-      session_id: str,
-  ) -> ListEventsResponse:
-    raise NotImplementedError()
diff --git a/src/google/adk/sessions/vertex_ai_session_service.py b/src/google/adk/sessions/vertex_ai_session_service.py
index 8387de6..c49c43a 100644
--- a/src/google/adk/sessions/vertex_ai_session_service.py
+++ b/src/google/adk/sessions/vertex_ai_session_service.py
@@ -25,7 +25,6 @@ from ..events.event_actions import EventActions
 from . import _session_util
 from .base_session_service import BaseSessionService
 from .base_session_service import GetSessionConfig
-from .base_session_service import ListEventsResponse
 from .base_session_service import ListSessionsResponse
 from .session import Session
 
@@ -213,33 +212,6 @@ class VertexAiSessionService(BaseSessionService):
         request_dict={},
     )
 
-  @override
-  def list_events(
-      self,
-      *,
-      app_name: str,
-      user_id: str,
-      session_id: str,
-  ) -> ListEventsResponse:
-    reasoning_engine_id = _parse_reasoning_engine_id(app_name)
-    api_response = self.api_client.request(
-        http_method='GET',
-        path=f'reasoningEngines/{reasoning_engine_id}/sessions/{session_id}/events',
-        request_dict={},
-    )
-
-    logger.info(f'List events response {api_response}')
-
-    # Handles empty response case
-    if api_response.get('httpHeaders', None):
-      return ListEventsResponse()
-
-    session_events = api_response['sessionEvents']
-
-    return ListEventsResponse(
-        events=[_from_api_event(event) for event in session_events]
-    )
-
   @override
   def append_event(self, session: Session, event: Event) -> Event:
     # Update the in-memory session.