This study compared the effectiveness of developmental education for parents with parent education in child management and with a no-education control condition in motivating parents to participate in home treatment programs for developmentally delayed infants. 39 delayed infants, matched for age and severity of delay, and their families were randomly assigned to the 3 treatment groups. The subsequent differential effectiveness of home treatment programs, in terms of the infants' developmental gains, was then examined. Results indicated that the children in the developmental education group gained a greater number of skills, and their parents participated more in the assigned home treatment programs than did parents in the other 2 groups. At follow-up approximately 1 year later, parents who received developmental education continued to participate more than the other parents in their child's treatment program. Developmental education appears to enable parents to discriminate small developmental gains, facilitating the intrinsic motivation involved in working with their children.