This article reports the results of a study of lay conceptions of autism. The subjects were 33 parents of autistic children. The study utilized Kleinman's explanatory model perspective and examined parents' beliefs about autism with respect to the nature and onset of symptoms, the etiology of the affliction and the illness outcomes for their children. The parents' explanatory models varied in significant ways from the biomedical perspective on autism. The results also identified gender based differences regarding parental beliefs about the etiology of the illness.