MDMA is a potential novel treatment for post-traumatic stress disorder (PTSD). Our goal is to review current knowledge on MDMA and its use in MDMA-assisted psychotherapy for PTSD. Literature searches were done on PubMed, Web of Science and Google Scholar and references reviewed in identified articles. MDMA-assisted therapy for PTSD usually consists of a few preparatory sessions before two or three sessions where one or two oral doses of MDMA are given along with supportive psychotherapy. The therapy is delivered in the presence of two therapists for about eight hours each time. In addition, the patient receives up to 9 integrative sessions in due course. This use of MDMA as a part of psychotherapy for PTSD is proposed to lessen the psychological distress that often arises in the processing of traumatic events to facilitate the treatment process and reduce the risk of drop-out. Recent studies indicate that MDMA-assisted psychotherapy reduces PTSD symptoms and is generally well tolerated. These studies are necessary if this MDMA-assisted treatment is to be approved by licensing authorities. There is an urgent need for new effective treatments for PTSD and for comparisons between this MDMA-assisted psychotherapy and currently approved psychotherapies with and without MDMA-use.