diff --git a/cartographer_ros/cartographer_ros/map_builder_bridge.cc b/cartographer_ros/cartographer_ros/map_builder_bridge.cc
index ea51b9a..5162a53 100644
--- a/cartographer_ros/cartographer_ros/map_builder_bridge.cc
+++ b/cartographer_ros/cartographer_ros/map_builder_bridge.cc
@@ -22,6 +22,7 @@
 #include "cartographer/io/proto_stream.h"
 #include "cartographer/mapping/pose_graph.h"
 #include "cartographer_ros/msg_conversion.h"
+#include "cartographer_ros/time_conversion.h"
 #include "cartographer_ros_msgs/StatusCode.h"
 #include "cartographer_ros_msgs/StatusResponse.h"
 
@@ -258,6 +259,30 @@ MapBuilderBridge::GetLocalTrajectoryData() {
   return local_trajectory_data;
 }
 
+void MapBuilderBridge::HandleTrajectoryQuery(
+    cartographer_ros_msgs::TrajectoryQuery::Request& request,
+    cartographer_ros_msgs::TrajectoryQuery::Response& response) {
+  // This query is safe if the trajectory doesn't exist (returns 0 poses).
+  // However, we can filter unwanted states at the higher level in the node.
+  const auto node_poses = map_builder_->pose_graph()->GetTrajectoryNodePoses();
+  for (const auto& node_id_data :
+       node_poses.trajectory(request.trajectory_id)) {
+    if (!node_id_data.data.constant_pose_data.has_value()) {
+      continue;
+    }
+    geometry_msgs::PoseStamped pose_stamped;
+    pose_stamped.header.frame_id = node_options_.map_frame;
+    pose_stamped.header.stamp =
+        ToRos(node_id_data.data.constant_pose_data.value().time);
+    pose_stamped.pose = ToGeometryMsgPose(node_id_data.data.global_pose);
+    response.trajectory.push_back(pose_stamped);
+  }
+  response.status.code = cartographer_ros_msgs::StatusCode::OK;
+  response.status.message = absl::StrCat(
+      "Retrieved ", response.trajectory.size(),
+      " trajectory nodes from trajectory ", request.trajectory_id, ".");
+}
+
 visualization_msgs::MarkerArray MapBuilderBridge::GetTrajectoryNodeList() {
   visualization_msgs::MarkerArray trajectory_node_list;
   const auto node_poses = map_builder_->pose_graph()->GetTrajectoryNodePoses();
diff --git a/cartographer_ros/cartographer_ros/map_builder_bridge.h b/cartographer_ros/cartographer_ros/map_builder_bridge.h
index a9ede0a..1a54e65 100644
--- a/cartographer_ros/cartographer_ros/map_builder_bridge.h
+++ b/cartographer_ros/cartographer_ros/map_builder_bridge.h
@@ -34,6 +34,8 @@
 #include "cartographer_ros_msgs/SubmapEntry.h"
 #include "cartographer_ros_msgs/SubmapList.h"
 #include "cartographer_ros_msgs/SubmapQuery.h"
+#include "cartographer_ros_msgs/TrajectoryQuery.h"
+#include "geometry_msgs/TransformStamped.h"
 #include "nav_msgs/OccupancyGrid.h"
 
 // Abseil unfortunately pulls in winnt.h, which #defines DELETE.
@@ -84,6 +86,9 @@ class MapBuilderBridge {
   void HandleSubmapQuery(
       cartographer_ros_msgs::SubmapQuery::Request& request,
       cartographer_ros_msgs::SubmapQuery::Response& response);
+  void HandleTrajectoryQuery(
+      cartographer_ros_msgs::TrajectoryQuery::Request& request,
+      cartographer_ros_msgs::TrajectoryQuery::Response& response);
 
   std::map<int /* trajectory_id */,
            ::cartographer::mapping::PoseGraphInterface::TrajectoryState>
diff --git a/cartographer_ros/cartographer_ros/node.cc b/cartographer_ros/cartographer_ros/node.cc
index 437bad4..6ed5dad 100644
--- a/cartographer_ros/cartographer_ros/node.cc
+++ b/cartographer_ros/cartographer_ros/node.cc
@@ -128,6 +128,8 @@ Node::Node(
           kConstraintListTopic, kLatestOnlyPublisherQueueSize);
   service_servers_.push_back(node_handle_.advertiseService(
       kSubmapQueryServiceName, &Node::HandleSubmapQuery, this));
+  service_servers_.push_back(node_handle_.advertiseService(
+      kTrajectoryQueryServiceName, &Node::HandleTrajectoryQuery, this));
   service_servers_.push_back(node_handle_.advertiseService(
       kStartTrajectoryServiceName, &Node::HandleStartTrajectory, this));
   service_servers_.push_back(node_handle_.advertiseService(
@@ -174,6 +176,23 @@ bool Node::HandleSubmapQuery(
   return true;
 }
 
+bool Node::HandleTrajectoryQuery(
+    ::cartographer_ros_msgs::TrajectoryQuery::Request& request,
+    ::cartographer_ros_msgs::TrajectoryQuery::Response& response) {
+  absl::MutexLock lock(&mutex_);
+  response.status = TrajectoryStateToStatus(
+      request.trajectory_id,
+      {TrajectoryState::ACTIVE, TrajectoryState::FINISHED,
+       TrajectoryState::FROZEN} /* valid states */);
+  if (response.status.code != cartographer_ros_msgs::StatusCode::OK) {
+    LOG(ERROR) << "Can't query trajectory from pose graph: "
+               << response.status.message;
+    return true;
+  }
+  map_builder_bridge_.HandleTrajectoryQuery(request, response);
+  return true;
+}
+
 void Node::PublishSubmapList(const ::ros::WallTimerEvent& unused_timer_event) {
   absl::MutexLock lock(&mutex_);
   submap_list_publisher_.publish(map_builder_bridge_.GetSubmapList());
@@ -485,22 +504,21 @@ cartographer_ros_msgs::StatusResponse Node::TrajectoryStateToStatus(
   const auto trajectory_states = map_builder_bridge_.GetTrajectoryStates();
   cartographer_ros_msgs::StatusResponse status_response;
 
-  if (!(trajectory_states.count(trajectory_id))) {
+  const auto it = trajectory_states.find(trajectory_id);
+  if (it == trajectory_states.end()) {
     status_response.message =
         absl::StrCat("Trajectory ", trajectory_id, " doesn't exist.");
     status_response.code = cartographer_ros_msgs::StatusCode::NOT_FOUND;
     return status_response;
   }
 
-  const auto trajectory_state = trajectory_states.at(trajectory_id);
   status_response.message =
       absl::StrCat("Trajectory ", trajectory_id, " is in '",
-                   TrajectoryStateToString(trajectory_state), "' state.");
-  if (valid_states.count(trajectory_state)) {
-    status_response.code = cartographer_ros_msgs::StatusCode::OK;
-  } else {
-    status_response.code = cartographer_ros_msgs::StatusCode::INVALID_ARGUMENT;
-  }
+                   TrajectoryStateToString(it->second), "' state.");
+  status_response.code =
+      valid_states.count(it->second)
+          ? cartographer_ros_msgs::StatusCode::OK
+          : cartographer_ros_msgs::StatusCode::INVALID_ARGUMENT;
   return status_response;
 }
 
diff --git a/cartographer_ros/cartographer_ros/node.h b/cartographer_ros/cartographer_ros/node.h
index d55749f..690487c 100644
--- a/cartographer_ros/cartographer_ros/node.h
+++ b/cartographer_ros/cartographer_ros/node.h
@@ -134,6 +134,9 @@ class Node {
   bool HandleSubmapQuery(
       cartographer_ros_msgs::SubmapQuery::Request& request,
       cartographer_ros_msgs::SubmapQuery::Response& response);
+  bool HandleTrajectoryQuery(
+      ::cartographer_ros_msgs::TrajectoryQuery::Request& request,
+      ::cartographer_ros_msgs::TrajectoryQuery::Response& response);
   bool HandleStartTrajectory(
       cartographer_ros_msgs::StartTrajectory::Request& request,
       cartographer_ros_msgs::StartTrajectory::Response& response);
diff --git a/cartographer_ros/cartographer_ros/node_constants.h b/cartographer_ros/cartographer_ros/node_constants.h
index b819121..f54a4ab 100644
--- a/cartographer_ros/cartographer_ros/node_constants.h
+++ b/cartographer_ros/cartographer_ros/node_constants.h
@@ -35,6 +35,7 @@ constexpr char kOccupancyGridTopic[] = "map";
 constexpr char kScanMatchedPointCloudTopic[] = "scan_matched_points2";
 constexpr char kSubmapListTopic[] = "submap_list";
 constexpr char kSubmapQueryServiceName[] = "submap_query";
+constexpr char kTrajectoryQueryServiceName[] = "trajectory_query";
 constexpr char kStartTrajectoryServiceName[] = "start_trajectory";
 constexpr char kWriteStateServiceName[] = "write_state";
 constexpr char kGetTrajectoryStatesServiceName[] = "get_trajectory_states";
diff --git a/cartographer_ros_msgs/CMakeLists.txt b/cartographer_ros_msgs/CMakeLists.txt
index e4daaff..15c86de 100644
--- a/cartographer_ros_msgs/CMakeLists.txt
+++ b/cartographer_ros_msgs/CMakeLists.txt
@@ -51,6 +51,7 @@ add_service_files(
     ReadMetrics.srv
     StartTrajectory.srv
     SubmapQuery.srv
+    TrajectoryQuery.srv
     WriteState.srv
 )
 
diff --git a/cartographer_ros_msgs/srv/TrajectoryQuery.srv b/cartographer_ros_msgs/srv/TrajectoryQuery.srv
new file mode 100644
index 0000000..ca5da3b
--- /dev/null
+++ b/cartographer_ros_msgs/srv/TrajectoryQuery.srv
@@ -0,0 +1,18 @@
+# Copyright 2019 The Cartographer Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+int32 trajectory_id
+---
+cartographer_ros_msgs/StatusResponse status
+geometry_msgs/PoseStamped[] trajectory