A best-evidence synthesis and meta-analysis were conducted to evaluate interventions designed to decrease noncompliance in early childhood settings. Studies were examined for quality, intervention components, and outcomes for young children (ages 2–8 years) across settings. Results indicated most designs were high-quality and produced desired outcomes. However, participant inclusion criteria were commonly underreported, and social and ecological validity data were absent. Thus, for whom noncompliance interventions are effective, appropriate, feasible, or preferred is largely unknown. Contrary to prior evidence from the broader challenging behavior literature, function-based assessments had no impact on intervention outcomes. Reasons for this finding are explored, including the narrow application of function-based assessment findings to compliance interventions. Future implications for research and practice are presented. (author abstract)