There is literature suggesting that some demographic characteristics actually can influence how parents or caregivers respond on informant-based measures for their children. The current study aimed to expand that research to include analysis of the relationship of maternal age and education level on mothers' ratings of their child's ASD by inspecting the total score on the "Autism Spectrum Disorders-Diagnostic for Children" ("ASD-DC"). We investigated biological mothers' ratings of 73 children (5-16 years of age), all of who had ASD diagnoses. Informants were classified into one of three age groups ([less than or equal to]34 years; 35-40 years; [greater than or equal to]41 years) and one of two education groups (high school graduate; university graduate). Following a two-way ANOVA, a significant interaction effect was found for informant age group and education level on total scores of the "ASD-DC". Within the [greater than or equal to]41 age group, ratings of ASD increased (indicating greater impairment) as the informants' education level increased. A reverse trend was established in the other two age groups. Further findings and implications are discussed. (Contains 1 figure and 1 table.)