diff --git a/analytics-service/src/main/java/com/kt/event/analytics/config/SampleDataLoader.java b/analytics-service/src/main/java/com/kt/event/analytics/config/SampleDataLoader.java
index 72d27f4..527e840 100644
--- a/analytics-service/src/main/java/com/kt/event/analytics/config/SampleDataLoader.java
+++ b/analytics-service/src/main/java/com/kt/event/analytics/config/SampleDataLoader.java
@@ -286,6 +286,11 @@ public class SampleDataLoader implements ApplicationRunner {
 
                 publishEvent(PARTICIPANT_REGISTERED_TOPIC, event);
                 totalPublished++;
+
+                // 동시성 충돌 방지: 10개마다 100ms 대기
+                if ((j + 1) % 10 == 0) {
+                    Thread.sleep(100);
+                }
             }
         }
 
diff --git a/analytics-service/src/main/java/com/kt/event/analytics/messaging/consumer/DistributionCompletedConsumer.java b/analytics-service/src/main/java/com/kt/event/analytics/messaging/consumer/DistributionCompletedConsumer.java
index 1b3d1d1..0d77956 100644
--- a/analytics-service/src/main/java/com/kt/event/analytics/messaging/consumer/DistributionCompletedConsumer.java
+++ b/analytics-service/src/main/java/com/kt/event/analytics/messaging/consumer/DistributionCompletedConsumer.java
@@ -11,6 +11,7 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.data.redis.core.RedisTemplate;
 import org.springframework.kafka.annotation.KafkaListener;
 import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Transactional;
 
 import java.util.List;
 import java.util.concurrent.TimeUnit;
@@ -37,7 +38,10 @@ public class DistributionCompletedConsumer {
 
     /**
      * DistributionCompleted 이벤트 처리 (설계서 기준 - 여러 채널 배열)
+     *
+     * @Transactional 필수: DB 저장 작업을 위해 트랜잭션 컨텍스트 필요
      */
+    @Transactional
     @KafkaListener(topics = "sample.distribution.completed", groupId = "${spring.kafka.consumer.group-id}")
     public void handleDistributionCompleted(String message) {
         try {
@@ -128,8 +132,8 @@ public class DistributionCompletedConsumer {
                 .mapToInt(ChannelStats::getImpressions)
                 .sum();
 
-            // EventStats 업데이트
-            eventStatsRepository.findByEventId(eventId)
+            // EventStats 업데이트 - 비관적 락 적용
+            eventStatsRepository.findByEventIdWithLock(eventId)
                 .ifPresentOrElse(
                     eventStats -> {
                         eventStats.setTotalViews(totalViews);
diff --git a/analytics-service/src/main/java/com/kt/event/analytics/messaging/consumer/EventCreatedConsumer.java b/analytics-service/src/main/java/com/kt/event/analytics/messaging/consumer/EventCreatedConsumer.java
index c7c7689..5f8cb84 100644
--- a/analytics-service/src/main/java/com/kt/event/analytics/messaging/consumer/EventCreatedConsumer.java
+++ b/analytics-service/src/main/java/com/kt/event/analytics/messaging/consumer/EventCreatedConsumer.java
@@ -10,6 +10,7 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.data.redis.core.RedisTemplate;
 import org.springframework.kafka.annotation.KafkaListener;
 import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Transactional;
 
 import java.util.concurrent.TimeUnit;
 
@@ -34,7 +35,10 @@ public class EventCreatedConsumer {
 
     /**
      * EventCreated 이벤트 처리 (MVP용 샘플 토픽)
+     *
+     * @Transactional 필수: DB 저장 작업을 위해 트랜잭션 컨텍스트 필요
      */
+    @Transactional
     @KafkaListener(topics = "sample.event.created", groupId = "${spring.kafka.consumer.group-id}")
     public void handleEventCreated(String message) {
         try {
diff --git a/analytics-service/src/main/java/com/kt/event/analytics/messaging/consumer/ParticipantRegisteredConsumer.java b/analytics-service/src/main/java/com/kt/event/analytics/messaging/consumer/ParticipantRegisteredConsumer.java
index ae33697..54d2fb5 100644
--- a/analytics-service/src/main/java/com/kt/event/analytics/messaging/consumer/ParticipantRegisteredConsumer.java
+++ b/analytics-service/src/main/java/com/kt/event/analytics/messaging/consumer/ParticipantRegisteredConsumer.java
@@ -10,6 +10,7 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.data.redis.core.RedisTemplate;
 import org.springframework.kafka.annotation.KafkaListener;
 import org.springframework.stereotype.Component;
+import org.springframework.transaction.annotation.Transactional;
 
 import java.util.concurrent.TimeUnit;
 
@@ -34,7 +35,10 @@ public class ParticipantRegisteredConsumer {
 
     /**
      * ParticipantRegistered 이벤트 처리 (MVP용 샘플 토픽)
+     *
+     * @Transactional 필수: 비관적 락 사용을 위해 트랜잭션 컨텍스트 필요
      */
+    @Transactional
     @KafkaListener(topics = "sample.participant.registered", groupId = "${spring.kafka.consumer.group-id}")
     public void handleParticipantRegistered(String message) {
         try {
@@ -51,8 +55,8 @@ public class ParticipantRegisteredConsumer {
                 return;
             }
 
-            // 2. 이벤트 통계 업데이트 (참여자 수 +1)
-            eventStatsRepository.findByEventId(eventId)
+            // 2. 이벤트 통계 업데이트 (참여자 수 +1) - 비관적 락 적용
+            eventStatsRepository.findByEventIdWithLock(eventId)
                 .ifPresentOrElse(
                     eventStats -> {
                         eventStats.incrementParticipants();
diff --git a/analytics-service/src/main/java/com/kt/event/analytics/repository/EventStatsRepository.java b/analytics-service/src/main/java/com/kt/event/analytics/repository/EventStatsRepository.java
index 1b13bfa..02688a9 100644
--- a/analytics-service/src/main/java/com/kt/event/analytics/repository/EventStatsRepository.java
+++ b/analytics-service/src/main/java/com/kt/event/analytics/repository/EventStatsRepository.java
@@ -1,7 +1,11 @@
 package com.kt.event.analytics.repository;
 
 import com.kt.event.analytics.entity.EventStats;
+import jakarta.persistence.LockModeType;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Lock;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 
 import java.util.Optional;
@@ -20,6 +24,20 @@ public interface EventStatsRepository extends JpaRepository<EventStats, Long> {
      */
     Optional<EventStats> findByEventId(String eventId);
 
+    /**
+     * 이벤트 ID로 통계 조회 (비관적 락 적용)
+     *
+     * 동시성 충돌 방지를 위해 PESSIMISTIC_WRITE 락 사용
+     * - 읽는 순간부터 락을 걸어 다른 트랜잭션 차단
+     * - ParticipantRegistered 이벤트 처리 시 사용
+     *
+     * @param eventId 이벤트 ID
+     * @return 이벤트 통계
+     */
+    @Lock(LockModeType.PESSIMISTIC_WRITE)
+    @Query("SELECT e FROM EventStats e WHERE e.eventId = :eventId")
+    Optional<EventStats> findByEventIdWithLock(@Param("eventId") String eventId);
+
     /**
      * 매장 ID와 이벤트 ID로 통계 조회
      *