We examined the efficacy of divalproex sodium (DVP) for the treatment of PTSD in conduct disorder, utilizing a previous study in which 71 youth were enrolled in a randomized controlled clinical trial. Twelve had PTSD. Subjects (all males, mean age 16, SD 1.0) were randomized into high and low dose conditions. Clinical Global Impression (CGI) ratings for core PTSD symptoms (Intrusion, avoidance and hyper arousal) were primary outcome measures, weekly slopes of impulsivity secondary ones. Intent-to-treat analyses showed significant positive associations between receiving high dose of DVP CGI's. Parallel analyses comparing outcome by drug level achieved strengthened the results.