Despite recent studies indicating the high prevalence of autism spectrum disorders (ASDs), there has been little focus on improving ASD education during pediatric residency training. The objective of this study was to evaluate a new curriculum developed in partnership with the Centers for Disease Control and Prevention and the Maternal and Child Health Bureau about ASDs. "Autism Case Training (ACT): A Developmental-Behavioral Pediatrics Curriculum" consists of 7 case-based teaching modules. Modules were facilitated by faculty at 26 pediatric residency programs and data were obtained on 114 residents. Pre- and post-test data revealed significant short-term improvements in residents' knowledge and self-assessed competence regarding ASDs. Findings suggest that the ACT curriculum is effective in enhancing training about ASDs in pediatric residency programs.