Risk factors for cancer of the tongue in Uruguay. From 1987 to 1989, a hospital-based case-control study of cancer of the tongue was conducted in Montevideo, Uruguay, as part of a large study to investigate a number of risk factors for cancer of the oral cavity, pharynx, and larynx. The study involved interviews with 57 cases and 353 controls and was restricted to men. Relative risks (RR) associated with tobacco smoking, alcohol drinking, and selected dietary items were obtained by unconditional logistic-regression analysis. Users of black tobacco had a RR fourfold higher than users of blond tobacco, and heavy drinkers of alcohol had a RR of 11.6. Infrequent consumption of vegetables was associated with a significant RR of 5.3, and heavy drinkers of the local infusion "mate" had a RR of 2.5. It was concluded that black tobacco smoking and alcohol drinking were the strongest risk factors for cancer of the tongue in Uruguay. Their effects combine according to a multiplicative model. Also, infrequent vegetable intake and mate ingestion contribute to the risk of cancer of the tongue. 