This study examined the effects of coaching on the implementation of functional assessment--based parent intervention in reducing children's challenging behaviors. A multiple baseline across participants design was used with three parent-child dyads with children between the ages of 2 and 5 years. The intervention consisted of training and delayed coaching to examine the effects of coaching following the training session. Results document that when coaching was provided, parents were able to implement the function-based strategies consistently at a high level, which resulted in the reduction of children's challenging behaviors. Contributions to the literature, implications, and future directions are discussed.