In a case-control study of 302 male and 65 female bladder cancer patients and an equal number of other patients matched to them in age, sex, hospital, and hospital-room status, no association was found between use of artificial sweeteners or diet beverages and bladder cancer. No dose-response was observed with respect to quantity or duration of use of the two combined. No evidence was found to suggest that artificial sweeteners or diet beverages promote the tumorigenic effect of tobacco smoking. Artificial sweetener and diet beverage use strongly reflected socioeconomic status among controls with various diagnoses.