Autism Spectrum Disorders (ASDs) are complex neurodevelopmental disorders with many biological causes, including genetic, syndromic and environmental. Such etiologic heterogeneity impacts considerably upon parents' needs for understanding their child's diagnosis. A descriptive survey was designed to investigate parental views on the cause(s) of ASD in their child. Among the 41 parents who replied to the questionnaire, genetic influences (90.2%), perinatal factors (68.3%), diet (51.2%), prenatal factors (43.9%) and vaccines (40.0%) were considered to be the most significant contributory factors. Parents reported inaccurately high recurrence risks, misperceptions of the contribution of various putative factors, feelings of guilt and blame regarding their child's diagnosis, as well as a lack of advocacy for genetic counseling by non-geneticist professionals. This study offers clinicians and researchers further insight into what parents believe contributed to their child's diagnosis of ASD and will help facilitate genetic counseling for these families.