The use of classic psychedelics in the treatment of alcohol use disorder dates to Hoffer and Osmond’s work with LSD in Saskatchewan starting in 1953. Initially seen as a way to safely induce a delirium tremens-like experience, LSD was tested in clinical trials and used in treatment programs for thousands of patients through the early 1970s, resulting in substantial but inconclusive evidence for its effectiveness. With increasing restriction of access to psychedelics for reach purposes, LSD research ceased in the early 1970’s. 40 years later, research with psilocybin, a chemically similar but shorter acting and naturally occurring compound, has shown that psilocybin-assisted treatment of alcohol use disorder is feasible and potentially effective. This presentation gives an overview of the history of the use of classic psychedelics in treatment of alcohol use disorder and discusses the designs of a completed open-label pilot and ongoing phase II double-blind trial. The psychotherapy model and structure of psilocybin sessions, possible mechanisms of action, and participants’ descriptions of the psilocybin experience are included. Interim findings of 12-week outcomes from phase II trial participants will be presented.