This article reviews the scientific support for the various medications that have been prescribed for patients with PTSD, with major attention to randomized clinical trials. The strongest evidence is for antidepressant medications, especially selective serotonin and serotonin/norepinephrine reuptake inhibitors. With the exception of prazosin, there is little evidence for the effectiveness of antiadrenergic agents either for monotherapy or for prevention of PTSD. Other classes of medications that are not recommended at this time include anticonvulsants, benzodiazepines, and atypical antipsychotic agents. Hopefully, this review will help clinicians make evidence-based decisions as they strive to provide the most effective treatment for patients with PTSD. Looking ahead, ongoing clinical trials are investigating preventive agents, monotherapeutic interventions, adjunctive treatments, and medications that enhance psychotherapy. In short, we are on the threshold of exciting new developments in research on pharmacotherapy for PTSD with the hope that effective novel treatments will soon be available for clinical use. In this paper, I will review the scientific support for the various medications that have been prescribed for patients with PTSD. Frankly, the evidence supporting some is much stronger than that for others. Hopefully, this review will help clinicians make evidence-based decisions as they strive to provide the most effective treatment for patients with PTSD. The literature search for this review focused primarily on randomized clinical trials cataloged in the National Center for PTSD’s PILOTS bibliographic database and from the Agency for Healthcare Research and Quality’s recent meta-analysis of treatments for PTSD.