diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/query/Criteria.java b/spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/query/Criteria.java
index beb0c68a9..621eff83a 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/query/Criteria.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/query/Criteria.java
@@ -123,7 +123,7 @@ public class Criteria implements CriteriaDefinition {
 	 * @return
 	 */
 	public Criteria nin(Object... o) {
-		criteria.put("$min", o);
+		criteria.put("$nin", o);
 		return this;
 	}
 
diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/repository/MongoQueryCreator.java b/spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/repository/MongoQueryCreator.java
index e4e07acc0..f5478b68d 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/repository/MongoQueryCreator.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/document/mongodb/repository/MongoQueryCreator.java
@@ -17,6 +17,7 @@ package org.springframework.data.document.mongodb.repository;
 
 import static org.springframework.data.document.mongodb.query.Criteria.*;
 
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.regex.Pattern;
@@ -141,6 +142,10 @@ class MongoQueryCreator extends AbstractQueryCreator<Query, Criteria> {
             return criteria.not().is(null);
         case IS_NULL:
             return criteria.is(null);
+        case NOT_IN:
+        	return criteria.nin(nextAsArray(parameters));
+        case IN:
+        	return criteria.in(nextAsArray(parameters));
         case LIKE:
             String value = parameters.next().toString();
             return criteria.is(toLikeRegex(value));
@@ -154,6 +159,17 @@ class MongoQueryCreator extends AbstractQueryCreator<Query, Criteria> {
     }
 
 
+    private Object[] nextAsArray(Iterator<Object> iterator) {
+    	Object next = iterator.next();
+    	
+    	if (next instanceof Collection) {
+    		return ((Collection<?>) next).toArray();
+    	} else if (next.getClass().isArray()) {
+    		return (Object[]) next;
+    	}
+    	
+    	return new Object[] { next };
+    }
 
     private Pattern toLikeRegex(String source) {
 
diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/repository/AbstractPersonRepositoryIntegrationTests.java b/spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/repository/AbstractPersonRepositoryIntegrationTests.java
index 353aa34c6..14e31afe0 100644
--- a/spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/repository/AbstractPersonRepositoryIntegrationTests.java
+++ b/spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/repository/AbstractPersonRepositoryIntegrationTests.java
@@ -162,4 +162,21 @@ public abstract class AbstractPersonRepositoryIntegrationTests {
 		assertThat(result.size(), is(1));
 		assertThat(result, hasItem(dave));
 	}
+	
+	
+	@Test
+	public void findsPeopleByFirstnameInVarargs() {
+		
+		List<Person> result = repository.findByFirstnameIn("Dave", "Carter");
+		assertThat(result.size(), is(2));
+		assertThat(result, hasItems(dave, carter));
+	}
+	
+	@Test
+	public void findsPeopleByFirstnameNotInCollection() {
+		
+		List<Person> result = repository.findByFirstnameNotIn(Arrays.asList("Boyd", "Carter"));
+		assertThat(result.size(), is(3));
+		assertThat(result, hasItems(dave, leroi, stefan));
+	}
 }
\ No newline at end of file
diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/repository/PersonRepository.java b/spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/repository/PersonRepository.java
index d9a0752db..b04bb88c5 100644
--- a/spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/repository/PersonRepository.java
+++ b/spring-data-mongodb/src/test/java/org/springframework/data/document/mongodb/repository/PersonRepository.java
@@ -15,6 +15,7 @@
  */
 package org.springframework.data.document.mongodb.repository;
 
+import java.util.Collection;
 import java.util.List;
 
 import org.springframework.data.domain.Page;
@@ -67,6 +68,21 @@ public interface PersonRepository extends MongoRepository<Person, String> {
      */
     Page<Person> findByLastnameLike(String lastname, Pageable pageable);
 
+	/**
+	 * Returns all {@link Person}s with a firstname contained in the given varargs.
+	 * 
+	 * @param firstnames
+	 * @return
+	 */
+	List<Person> findByFirstnameIn(String... firstnames);
+
+	/**
+	 * Returns all {@link Person}s with a firstname not contained in the given collection.
+	 * 
+	 * @param firstnames
+	 * @return
+	 */
+	List<Person> findByFirstnameNotIn(Collection<String> firstnames);
 
     /**
      * Returns all {@link Person}s with an age between the two given values.
diff --git a/src/main/resources/changelog.txt b/src/main/resources/changelog.txt
index 4c1af42cd..19ef84cf4 100644
--- a/src/main/resources/changelog.txt
+++ b/src/main/resources/changelog.txt
@@ -6,6 +6,7 @@ Changes in version 1.0.0.M2 MongoDB
 
 Repository
 * Adapted new metamodel API (DATADOC-47, DATACMNS-17)
+* Added support for 'In' and 'NotIn' keyword (DATADOC-46)
 
 Changes in version 1.0.0.M1 MongoDB (2011-02-14)
 ------------------------------------------------