This review examines how recommended practices for toddlers with autism spectrum disorders (ASD) are integrated into interventions in the first generation of research targeting toddlers with ASD. The purpose was not to review intervention effectiveness, which is addressed in other reviews; rather, it was to assess reported intervention methods in relation to principles distilled from early intervention policy and validated practice guidelines for toddlers and families. These principles include family-centered and family-supportive practice, natural environments, promotion of active child participation in learning, and functional and systematic practices that consider developmental readiness and unique variations in learning. A small minority of reported interventions (5 of 27) fully addressed each principle, revealing a substantial gap between principles and intervention research practices. The most pronounced gaps concerned natural/inclusive environments and family-centered/family-supportive practices. Recommendations for future research are presented. (Contains 3 tables.)