Obsessive-compulsive disorder (OCD) is a neuropsychiatric disorder that causes significant distress to the afflicted individual. About half of OCD patients treated with an adequate trial of serotonin reuptake inhibitors fail to fully respond to treatment and continue to exhibit significant symptoms. Therefore, there is a need for other agents to alleviate the symptoms of these disorders. In spite of considerable research including numerous randomized controlled trials and systematic reviews, there exists uncertainty regarding what treatments are effective. In this systematic review, we evaluated the efficacy of mood stabilizers in treatment-refractory OCD.