A program to help parents understand their child's developmental level was evaluated with 13 handicapped infants and their mothers. The intervention sought to increase parents' overall understanding of child development, improve their observational skills, and help them adjust their interactions by taking cues from the child's responses. Mental age and developmental quotients were computed for all children based on both child performance and parent reports for both Bayley mental and motor scales. Parental predictions of their child's performance on individual Bayley items were calculated and used as a measure of the inaccuracy of parental perceptions. A significant, negative relationship was found between parental inaccuracy and the child's developmental gain for the mental scale. Findings suggested that children of parents who are accurate in their perception of their child's developmental level show faster progress on developmental tasks than other children. (CL)