Reviewers analyzed studies published from 1990 to 2012 to determine early childhood practitioner involvement in functional behavioral assessment (FBA) and function-based behavioral intervention plans (BIP) for children with challenging behavior, age 6 and younger. Coding of 30 studies included practitioner involvement in FBA and BIP processes, training received to conduct FBAs and implement BIPs, and social validity and treatment integrity data. Findings indicate that early childhood practitioners had a limited role in FBAs and BIPs. Practitioner training occurred more often for the BIP than for the FBA. Approximately one fourth of the studies included a description of practitioners in a collaborative role with researchers during the FBA, and approximately one-half during the BIP process, even though practitioners implemented the BIP in the majority of studies reviewed. More than one half of the studies included social validity and/or treatment integrity measures.