Interpersonal psychotherapy (IPT) is a time-limited, diagnosis-targeted psychotherapy originally developed for the treatment of major depression. Research studies have repeatedly demonstrated its efficacy in treating mood disorders and other psychiatric disorders over the past 40 years. Because IPT is a life event−based treatment that focuses on improving interpersonal functioning, it seemed natural to adapt it for the treatment of posttraumatic stress disorder (PTSD), a life event−based illness that affects interpersonal functioning. Preliminary data have suggested that the efficacy of IPT in alleviating PTSD symptoms is equal to that of prolonged exposure, the best tested exposure-based treatment. We describe the principles of IPT and its modifications for treating PTSD. A case illustration describes a patient with PTSD related to military trauma. The authors discuss their reluctance to integrate IPT for PTSD with other psychotherapeutic perspectives. (PsycINFO Database Record (c) 2019 APA, all rights reserved)