Low or declining levels of serum cholesterol have been associated with increased mortality from cancer. We conducted a population-based cohort study of 1882 patients from one Danish county who received lipid-lowering drugs between January 1, 1991 and December 31, 1994. During the follow-up period of up to 4 years, 41 cancers were observed among users of lipid-lowering drugs, with 42.9 expected, to yield an age- and sex-standardized incidence ratio of 1.0 (95% confidence interval, 0.7-1.3). Although limited by small numbers and short follow-up period, examination by site of cancer and type of drug provided no evidence of an association. Further research is needed, however, with longer follow-up to assess more fully any potential cancer risk with these medications.