Objective: To examine the potential benefits of adding a selective serotonin reuptake inhibitor, sertraline, versus placebo, to trauma-focused cognitive-behavioral therapy (TF-CBT) for improving posttraumatic stress disorder and related psychological symptoms in children who have experienced sexual abuse. Method: Twenty-four 10- to 17-year-old female children and adolescents and their primary caretakers were randomly assigned to receive TF-CBT + sertraline or TF-CBT + placebo for 12 weeks. Results: Both groups experienced significant improvement in posttraumatic stress disorder and other clinical outcomes from pre- to posttreatment with no significant group x time differences between groups except in Child Global Assessment Scale ratings, which favored the TF-CBT + sertraline group. Conclusions: Only minimal evidence suggests a benefit to adding sertraline to TF-CBT. A drawback of adding sertraline was determining whether TF-CBT or sertraline caused clinical improvement for children with comorbid depression. Current evidence therefore supports an initial trial of TF-CBT or other evidence-supported psychotherapy for most children with PTSD symptoms before adding medication. (Contains 3 tables and 1 figure.)