Risperidone, an atypical antipsychotic medication, has gained wide acceptance as a first-line drug for several indications. Recently, interest has arisen in the use of risperidone as an adjunct therapy in post-traumatic stress disorder (PTSD). PTSD is a possible sequela of exposure to traumatic events. The military population, because of occupational exposure, is at a higher risk than the general population to develop PTSD, and the treatment of PTSD may be a significant issue for military practitioners. PTSD may be complicated by social issues and comorbid psychiatric conditions, and it is often difficult to treat. We present two case reports on the use of risperidone in the treatment of the intrusive thoughts and subsequent emotional reactivity experienced by some PTSD patients, along with a discussion of some possible mechanisms of action for the efficacy of risperidone in the treatment of these symptoms.