The purpose of this paper is to systematically review empirical evidence for the assessment and treatment of obsessive-compulsive disorder (OCD) among individuals with autism spectrum disorders (ASD). Systematic searches were conducted in electronic databases, reference lists, and journals. Fifty-five studies met inclusion criteria: 21 studies investigating prevalence, symptom presentation, and assessment, as well as 34 intervention studies investigating 14 different interventions. Based on the Chambless criteria for treatment efficacy, four treatments (behavior analysis and behavior modification, risperidone, fluoxetine, and fluvoxamine for adults) met criteria for possible efficacious interventions for OCD among individuals with ASD. Positive intervention outcomes were reported in the majority of studies, but there was not enough research to make firm conclusions regarding efficacy of other treatments.