diff --git a/src/main/java/de/thm/arsnova/dao/CouchDBDao.java b/src/main/java/de/thm/arsnova/dao/CouchDBDao.java
index 875b999c37a97d50ad1ec54f6769be7f6bc85a16..b1d11726ca84157834325eababc41b3b4705facb 100644
--- a/src/main/java/de/thm/arsnova/dao/CouchDBDao.java
+++ b/src/main/java/de/thm/arsnova/dao/CouchDBDao.java
@@ -1679,6 +1679,36 @@ public class CouchDBDao implements IDatabaseDao, ApplicationEventPublisherAware
 		}
 	}
 
+	@Override
+	public boolean deleteInactiveGuestSessions(long lastActivityBefore) {
+		try {
+			NovaView view = new NovaView("session/by_last_activity_for_guests");
+			view.setEndKey(lastActivityBefore);
+			List<Document> results = this.getDatabase().view(view).getResults();
+
+			final List<Document> newDocs = new ArrayList<Document>();
+			for (Document oldDoc : results) {
+				final Document newDoc = new Document();
+				newDoc.setId(oldDoc.getId());
+				newDoc.setRev(oldDoc.getJSONObject("value").getString("_rev"));
+				newDoc.put("_deleted", true);
+				newDocs.add(newDoc);
+				LOGGER.debug("Marked session document {} for deletion.", oldDoc.getId());
+			}
+
+			if (newDocs.size() > 0) {
+				getDatabase().bulkSaveDocuments(newDocs.toArray(new Document[newDocs.size()]));
+				LOGGER.info("Deleted {} inactive guest sessions.", newDocs.size());
+			}
+
+			return true;
+		} catch (IOException e) {
+			LOGGER.error("Could not delete inactive guest sessions.");
+		}
+
+		return false;
+	}
+
 	@Cacheable("lecturequestions")
 	@Override
 	public List<Question> getLectureQuestionsForUsers(final Session session) {
diff --git a/src/main/java/de/thm/arsnova/dao/IDatabaseDao.java b/src/main/java/de/thm/arsnova/dao/IDatabaseDao.java
index f5d2d2fb6af9bc0041e163a0586213cceb06a4d4..349d7b0d2c6029f00860fee99c85aab1379ae7df 100644
--- a/src/main/java/de/thm/arsnova/dao/IDatabaseDao.java
+++ b/src/main/java/de/thm/arsnova/dao/IDatabaseDao.java
@@ -146,6 +146,8 @@ public interface IDatabaseDao {
 
 	void deleteSession(Session session);
 
+	boolean deleteInactiveGuestSessions(long lastActivityBefore);
+
 	List<Question> getLectureQuestionsForUsers(Session session);
 
 	List<Question> getLectureQuestionsForTeachers(Session session);
diff --git a/src/main/java/de/thm/arsnova/services/ISessionService.java b/src/main/java/de/thm/arsnova/services/ISessionService.java
index 373f78d27b5ce813c0d374e0ca735ec17d954386..7b6c742068adb955a7e43845ac1ab90a88f7227d 100644
--- a/src/main/java/de/thm/arsnova/services/ISessionService.java
+++ b/src/main/java/de/thm/arsnova/services/ISessionService.java
@@ -91,6 +91,8 @@ public interface ISessionService {
 	SessionFeature changeSessionFeatures(String sessionkey, SessionFeature features);
 
 	boolean lockFeedbackInput(String sessionkey, Boolean lock);
-	
+
 	boolean flipFlashcards(String sessionkey, Boolean flip);
+
+	void deleteInactiveSessions();
 }
diff --git a/src/main/java/de/thm/arsnova/services/SessionService.java b/src/main/java/de/thm/arsnova/services/SessionService.java
index e2c4b94a80392acbe452cfc880c0a1638c30a7bd..a9aa671c9c0b3d70a35df770925d389499413074 100644
--- a/src/main/java/de/thm/arsnova/services/SessionService.java
+++ b/src/main/java/de/thm/arsnova/services/SessionService.java
@@ -47,6 +47,7 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.ApplicationEventPublisher;
 import org.springframework.context.ApplicationEventPublisherAware;
+import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.stereotype.Service;
 
@@ -98,6 +99,9 @@ public class SessionService implements ISessionService, ApplicationEventPublishe
 		}
 	}
 
+	private static final long SESSION_INACTIVITY_CHECK_INTERVAL_MS = 30 * 60 * 1000L;
+	private static final long SESSION_INACTIVITY_THRESHOLD_MS = 90 * 24 * 60 * 60 * 1000L;
+
 	@Autowired
 	private IDatabaseDao databaseDao;
 
@@ -123,6 +127,14 @@ public class SessionService implements ISessionService, ApplicationEventPublishe
 
 	public static final Logger LOGGER = LoggerFactory.getLogger(SessionService.class);
 
+	@Scheduled(fixedDelay = SESSION_INACTIVITY_CHECK_INTERVAL_MS)
+	public void deleteInactiveSessions() {
+		LOGGER.info("Delete inactive sessions.");
+		long unixTime = System.currentTimeMillis();
+		long lastActivityBefore = unixTime - SESSION_INACTIVITY_THRESHOLD_MS;
+		databaseDao.deleteInactiveGuestSessions(lastActivityBefore);
+	}
+
 	public void setDatabaseDao(final IDatabaseDao newDatabaseDao) {
 		databaseDao = newDatabaseDao;
 	}
diff --git a/src/test/java/de/thm/arsnova/dao/StubDatabaseDao.java b/src/test/java/de/thm/arsnova/dao/StubDatabaseDao.java
index c9bae3974ac242ad2b8cda3fb89a61ba839e40e6..ce0eda89f769066afc606ceb14533bf6797ce490 100644
--- a/src/test/java/de/thm/arsnova/dao/StubDatabaseDao.java
+++ b/src/test/java/de/thm/arsnova/dao/StubDatabaseDao.java
@@ -345,6 +345,12 @@ public class StubDatabaseDao implements IDatabaseDao {
 		// TODO Auto-generated method stub
 	}
 
+	@Override
+	public boolean deleteInactiveGuestSessions(long lastActivityBefore) {
+		// TODO Auto-generated method stub
+		return false;
+	}
+
 	@Override
 	public void deleteAllQuestionsWithAnswers(Session session) {
 		// TODO Auto-generated method stub