MongoDB Documentation, Release 3.0.4 Remove a Specific Index Remove All Indexes Modify an Index Step 1: Create a unique index. Step 2: Attempt to modify the index. For example, the following operation removes an ascending index on the tax-id field in the accounts collection: The operation returns a document with the status of the operation: Where the value of nIndexesWas reflects the number of indexes before removing this index. For text (page 500) indexes, pass the index name to the db.collection.dropIndex() method. See Use the Index Name to Drop a text Index (page 542) for details. You can also use the db.collection.dropIndexes() to remove all indexes, except for the _id index (page 487) from a collection. These shell helpers provide wrappers around the dropIndexes database command . Your client library may have a different or additional interface for these operations. To modify an existing index, you need to drop and recreate the index. Use the createIndex() method create a unique index. db.orders.createIndex( { "cust_id" : 1, "ord_date" : -1, "items" : 1 }, { unique: true } ) The method returns a document with the status of the results. The method only creates an index if the index does not already exist. See Create an Index (page 517) and Index Creation Tutorials (page 517) for more information on creating indexes. To modify an existing index, you cannot just re-issue the createIndex() method with the updated specification of the index. For example, the following operation attempts to remove the unique constraint from the previously created index by using the createIndex() method. The status document returned by the operation shows an error. db.orders.createIndex( { "cust_id" : 1, "ord_date" : -1, "items" : 1 } ) 525 8.3. Indexing Tutorials db.accounts.dropIndex( { "tax-id": 1 } ) { "nIndexesWas" : 3, "ok" : 1 } To remove an index, use the db.collection.dropIndex() method.