Substituting cannabis for alcohol may reduce drinking and related problems among alcohol-dependent individuals. Some even recommend prescribing medical cannabis to individuals attempting to reduce drinking. The primary aim of this review is to assess whether cannabis satisfies the seven previously published criteria for substitute medications for alcohol [e.g. ‘reduces alcohol-related harms’; ‘is safer in overdose than alcohol’; ‘should offer significant health economic benefits’; see Chick and Nutt ((2012) Substitution therapy for alcoholism: time for a reappraisal? J Psychopharmacol 26:205-12)].