diff --git a/localization/ekf_localizer/include/ekf_localizer/ekf_localizer.hpp b/localization/ekf_localizer/include/ekf_localizer/ekf_localizer.hpp
index 8f53e5a63af58..dc5e5659001dd 100644
--- a/localization/ekf_localizer/include/ekf_localizer/ekf_localizer.hpp
+++ b/localization/ekf_localizer/include/ekf_localizer/ekf_localizer.hpp
@@ -270,6 +270,11 @@ class EKFLocalizer : public rclcpp::Node
    */
   void updateSimple1DFilters(const geometry_msgs::msg::PoseWithCovarianceStamped & pose);
 
+  /**
+   * @brief initialize simple1DFilter
+   */
+  void initSimple1DFilters(const geometry_msgs::msg::PoseWithCovarianceStamped & pose);
+
   /**
    * @brief trigger node
    */
diff --git a/localization/ekf_localizer/src/ekf_localizer.cpp b/localization/ekf_localizer/src/ekf_localizer.cpp
index 3d1f2e8bab006..d505f5c528a35 100644
--- a/localization/ekf_localizer/src/ekf_localizer.cpp
+++ b/localization/ekf_localizer/src/ekf_localizer.cpp
@@ -351,7 +351,7 @@ void EKFLocalizer::callbackInitialPose(
 
   ekf_.init(X, P, params_.extend_state_step);
 
-  updateSimple1DFilters(*initialpose);
+  initSimple1DFilters(*initialpose);
 }
 
 /*
@@ -652,6 +652,25 @@ void EKFLocalizer::updateSimple1DFilters(const geometry_msgs::msg::PoseWithCovar
   pitch_filter_.update(pitch, pitch_dev, pose.header.stamp);
 }
 
+void EKFLocalizer::initSimple1DFilters(const geometry_msgs::msg::PoseWithCovarianceStamped & pose)
+{
+  double z = pose.pose.pose.position.z;
+  double roll = 0.0, pitch = 0.0, yaw_tmp = 0.0;
+
+  tf2::Quaternion q_tf;
+  tf2::fromMsg(pose.pose.pose.orientation, q_tf);
+  tf2::Matrix3x3(q_tf).getRPY(roll, pitch, yaw_tmp);
+
+  using COV_IDX = tier4_autoware_utils::xyzrpy_covariance_index::XYZRPY_COV_IDX;
+  double z_dev = pose.pose.covariance[COV_IDX::Z_Z];
+  double roll_dev = pose.pose.covariance[COV_IDX::ROLL_ROLL];
+  double pitch_dev = pose.pose.covariance[COV_IDX::PITCH_PITCH];
+
+  z_filter_.init(z, z_dev, pose.header.stamp);
+  roll_filter_.init(roll, roll_dev, pose.header.stamp);
+  pitch_filter_.init(pitch, pitch_dev, pose.header.stamp);
+}
+
 /**
  * @brief trigger node
  */