Smoking and drinking share many detrimental effects, some of which operate synergistically. Over 90% of alcoholic inpatients are smokers, with similar findings regarding outpatients. In the general population, the relationship between smoking and drinking appears positive but modest. Nicotine appears to facilitate ethanol consumption and vice versa. While ample theoretical viewpoints exist to explain the covariance of alcohol and cigarette consumption, conclusive data supporting one or another of these views are lacking. The assumption that alcoholics should be discouraged from quitting smoking as well as drinking is without empirical basis. Research should ascertain whether problem drinkers with greater positive association between alcohol and smoking benefit differentially from quitting both.