Objective: To determine the impact of a parent education and behavior management intervention (PEBM) on the mental health and adjustment of parents with preschool children with autism. Method: A randomized, group-comparison design involving a parent education and counseling intervention to control for nonspecific therapist effects and a control sample was used. Two metropolitan and two rural regions were randomly allocated to intervention groups (n = 70) or control (n = 35). The parents of consecutive children with autism (2 1/2-5 years old) from the autism assessment services for the intervention regions were then randomly allocated to either a 20-week manual-based parent education and behavior management intervention (n = 35) or a manual-based parent education and counseling intervention (n = 35). The main outcome measure of parental mental health was the General Health Questionnaire used pre- and postintervention and at 6-month follow-up. Results: Both treatments resulted in significant and progressive improvement in overall mental health at follow-up (F = 2, 97, p = 0.007) and mental health significantly improved over time in the 54% of principal caregivers who had the highest levels of mental health problems. The parent education and behavior management intervention was effective in alleviating a greater percentage of anxiety, insomnia, and somatic symptoms and family dysfunction than parent education and counseling at 6-month follow-up. Conclusions: A 20-week parent education and skills training program for parents of young children newly diagnosed with autism provides significant improvements in parental mental health and adjustment, justifying its addition to early intervention programs at least for parents with mental health problems. (Contains 1 figure and 4 tables.)