The association between traumatic events and psychopathology has long been recognized, and the literature on posttraumatic stress disorder (PTSD) has burgeoned since this entity was introduced into the diagnostic nomenclature. This literature has been characterized by a range of clinical controversies about the optimal diagnosis and treatment of PTSD. In response, several systematic reviews of treatment, clinical guidelines, and consensus statements about PTSD have been generated, but their conclusions are not always consistent. Our aim here is to provide a concise overview of the literature on PTSD, focusing in particular on recent investigations and publications, with the objective of summarizing practical clinical implications and suggesting future research opportunities. We consider, in turn, the diagnosis and evaluation, psychobiology, pharmacotherapy, psychotherapy, and prevention of PTSD.