This study investigated the relationship between repetitive behaviors in individuals with autism and obsessive-compulsive behaviors in parents. We hypothesized that repetitive behaviors in probands with autism would be associated with increased obsessive-compulsive behaviors in parents in sporadic families (1 known case of autism per family and no known history of autism). Parents with clinically significant Y-BOCS scores were more likely to have a family history of obsessive-compulsive disorder. The empirically derived Autism Diagnostic Interview-R (ADI-R) factor, Insistence on Sameness, was positively correlated with obsessive-compulsive behaviors in parents. Further, when probands were grouped on the basis of parental Y-BOCS scores (clinically significant versus non-clinically significant), probands whose parents had clinically significant Y-BOCS scores had higher ADI-R Insistence on Sameness factor scores. The findings of the current study of sporadic families extend previous work that has shown an association between restrictive/repetitive behaviors in probands with autism and obsessive-compulsive features in parents.