OBJECTIVE: To evaluate the effectiveness of an oral health educational intervention designed to increase proficiency of pediatric residents in oral health. METHODS: Pediatric residents at the University of North Carolina at Chapel Hill (UNC) participated in oral health education that included didactic sessions, hands-on instruction by pediatric dentists and residents, preventive dentistry prompts, and change strategies to introduce oral health into practice. Pediatric residents at East Carolina University (ECU), who had a short practicum in oral health, and Wake Forest University (WFU), who had no specific oral health instruction, served as comparison groups. All residents completed questionnaires before and 12 months after instruction began at UNC. Effects were tested for each school separately by repeated-measure analysis of variance. RESULTS: The mean percentage of UNC residents who answered 18 knowledge questions correctly and reported frequently performing 10 preventive dental practices increased by 17.7% and 65.1%, respectively, from baseline levels. Residents' confidence in performing 10 counseling and oral health screening activities improved by 17.9%. Opinions about including oral health in their clinical care improved only slightly. Changes at ECU and WFU were small, but low response rates in those schools preclude substantive conclusions from between schools comparisons. CONCLUSIONS: Multifaceted instruction in oral health was effective in improving pediatric residents' knowledge about oral health, their confidence in providing oral health services, and the delivery of these services in their ambulatory care practices. Residents also adopted the use of fluoride varnish, an innovation in pediatrics. More studies are needed to define the most efficient and effective residency-based instruction.