The need for effective treatments and treatment accessibility for obsessive-compulsive disorder (OCD) in childhood is evident given that as many as 50% of individuals with OCD report symptom onset before age 15. Despite the growing evidence supporting the efficacy of Exposure and Response Prevention (ERP) for youth with OCD, children seeking services for their OCD symptoms often do not receive ERP. Intensive treatment programs may be a feasible treatment option for children and their families who do not have access to ERP treatment and/or live in an area where therapists trained in ERP are limited. Preliminary studies have shown initial promise for 5-day intensive treatment programs, which have collapsed one-month intensive programs into an even shorter duration. This study serves as the first controlled, one-week intensive intervention for pediatric OCD. To evaluate the efficacy, feasibility, and acceptability of this brief, one-week intensive ERP program for pediatric OCD, nine children with OCD were randomized to a one-week, two-week, or three-week baseline period in a single-case, non-concurrent multiple baseline experimental design. Although symptoms were relatively stable during the baseline period, most participants showed reductions in OCD symptoms with the implementation of treatment. Treatment gains were maintained at a 3-month follow-up assessment; 67% of children were considered treatment responders. Children and families perceived the program to be acceptable, feasible, and beneficial. This study provides support for the efficacy and feasibility of a 5-day intensive treatment program for pediatric OCD. / Ph. D.