A case-control study was performed on 212 bladder cancer patients (165 male + 47 female) and 259 control persons (165 male + 94 female) matched according to age and geographic area. Twenty-five determinants of assumed importance were examined. Bivariate analysis revealed a significantly increased relative risk (RR) of developing bladder cancer associated with cigarette smoking, cigarillos smoking, pipe smoking, tobacco chewing, industrial work, previous venereal disease, work with petroleum or asphalt, consumption of alcohol, work with oil or gasoline, and work with chemical materials. A multivariate logistic analysis showed that cigarette and cigarillos smoking involved the highest significant risks. An analogous logistic analysis of the negatively associated determinants revealed never smokers and farmers to be the weakest independent variables.