The prevalence of five minor malformations and three palmar or finger crease abnormalities was determined in a total of 203 patients with urologic malignancies. An equal number of control individuals with acute infections or cardiopulmonary complaints was matched consecutively to the patients by sex and age. A significantly higher frequency of supernumerary nipples was found in all types of urologic tumors examined: the total prevalence was 32 of 203 in the patients, and four of 203 in the controls (p less than 0.001). Bifid uvula, preauricular pits, and abnormal palmar creases were also slightly more common in the patients, but the differences were not statistically significant.