Reasons for the underutilization of genetics services by families of children with autism spectrum disorders (ASD) are not well understood. We report the identification of factors associated with this underuse. Survey-based study of parents and/or guardians of children with ASD. One hundred fifty-five families completed the questionnaire. Thirty-one of 155 (20%) children had seen a genetics professional. Forty-nine of 154 (32%) children had undergone genetic testing. Parents whose child saw a genetics professional were more likely to 1) Have a primary provider refer for or suggest a genetics evaluation 2) Have asked for a referral, and/or 3) Know another person with a genetic cause of ASD. amilies of children with ASD who have not received genetics services are less aware of their availability and utility. They are also less likely to have their provider recommend a clinical genetics evaluation. Efforts should be taken to increase awareness of both health providers and parents regarding the usefulness of genetics services for ASD.