Cognitive‐behavioral therapy (CBT) using exposure with response prevention (ERP) is the treatment of choice for obsessive‐compulsive disorder (OCD); however, developmental modifications should be considered when treating young children. This article presents a case study illustrating family‐based CBT using ERP with a 7‐year‐old boy. The delivery of ERP for this case was guided by 3 main principles: (a) family involvement with a focus on reducing family accommodation, (b) understanding the functional relation between the client's obsessions and compulsions, and (c) creating conditions to facilitate habituation during exposure. Outcomes for this case indicate significant improvement in functioning and OCD symptoms. Results highlight the importance of family involvement and the applicability of using a function‐based habituation framework when delivering ERP to this unique population.