Findings from research syntheses of adult learning and in-service training studies identified the importance of professional development as a factor influencing practitioner use of recommended and evidence-based intervention practices. These relationships were used to test the hypothesis that practice-specific evidence-based capacity-building professional development would be related to early childhood practitioners’ reported use of recommended early childhood intervention practices. The participants were practitioners working with birth to 3-year-old, 3- to 5-year-old, or birth to 5-year-old children with identified disabilities, developmental delays, or at-risk conditions in home-based or center-based programs or both. The predictors included three practitioner background variables (e.g., years of professional experience) and three professional development variables (e.g., evidence-based professional development practices). Results indicated that the three professional development practice variables accounted for significant amounts of variance in the practitioners’ reported use of 10 different practices beyond that accounted for by the three background variables. The findings highlight the importance of evidence-based capacity-building professional development as a factor influencing practitioners’ judgments of their use of recommended practices. (author abstract)