Intraosseous ganglion cysts of the carpal bones located in the lunate are one of the rarely seen pathologic conditions. Here we present a case of the penetrating type of intraosseous ganglion cyst located in the lunate as an uncommon cause of wrist pain. The patient was successfully treated by surgical intervention. Intraosseous ganglion cyst should be considered in the differential diagnosis of chronic dull wrist pain.