This paper describes the self-reporting patterns of alcohol and drug consumption among male sex workers (MSWs) in three Australian cities during commercial sex encounters, and examines to what extent alcohol and drugs are used and whether this is related to the safe/unsafe outcome of the commercial sex encounter. One hundred and eighty-six MSWs from Brisbane, Sydney and Melbourne completed a diary following each commercial sex encounter over a two-week period. MSWs reported 2,087 commercial sex encounters during the study period. Alcohol or drug consumption was reported in 50.5% of the encounters. There were 488 instances of marijuana use reported before or during a commercial sex encounter, 210 instances of volatile inhalants use, 149 instances of heroine use and 151 of other drug use, including benzodiasepines, ecstasy, speed and cocaine. These substances were consumed either alone or combined. Marijuana consumption was associated with the commercial sex encounter occurring at the MSWs' place of residence and consumption of alcohol, marijuana and nitrites with the client's place. The results also reveal that consumption of drugs and alcohol was statistically related to length of the encounter, and that clients obtained through escort agencies or brothels were significantly associated with marijuana, other drug consumption and heroine use. Interestingly, a multivariate analysis indicated that encounters where the MSW consumed marijuana or did not consume any substance were less likely to have an unsafe outcome. The paper argues that it is necessary to identify and target risk groups and behaviours that are usually not included in broad based health education messages.