A case-control study, performed in two towns of Serbia (Yugoslavia) from 1990 to 1994, comprised 101 patients with histologically confirmed prostate cancer and 202 hospital controls individually matched by age (+/-2 years), hospital admittance and place of residence. Dietary information was obtained by using a standard questionnaire. After adjustment for possible confounders, risk factors for prostate cancer appeared to be the highest tertile of protein (odds ratio (OR) = 13.54, 95% confidence interval (CI) = 2.38-77.13), saturated fatty acid (OR = 3.63, 95% CI = 1.03-12.79), fibre (OR = 4.02, 95% CI = 1.38-11.73), and vitamin B12 intake (OR = 2.07, 95% CI = 1.08-3.97); a protective effect was found for the highest tertile of alpha-tocopherol (OR = 0.15, 95% CI = 0.05-0.53), calcium (OR = 0.37, 95% CI = 0.14-0.99) and iron intake (OR = 0.34, 95% CI = 0.12-0.95). There were significant (P < 0.05) linear trends in the odds ratios for alpha-tocopherol, vitamin B12, calcium and iron. According to logistic regression step by step analysis, risk factors for prostate cancer were dietary intake of retinol equivalent (OR = 1.64, 95% CI = 1.01-2.67) and vitamin B12 (OR = 1.87, 95% CI = 1.15-3.05), and a protective effect was found for dietary intake of iron (OR = 0.40, 95% CI = 0.27-0.58).