The reported data on the association of kidney and urinary tract malformations with supernumerary nipples are contradictory. We examined 200 children, ages 1 month-16 years, who were being followed because of recurrent urinary tract infection for supernumerary nipples. The patients were divided into two groups: those who were found to have urinary tract malformations on radiographic studies (n = 92) and those who were not (n = 108). All children were examined for any abnormal pigmentation along the milk line, and the entire body was examined for ectopic supernumerary nipples. Two of the children with proved urinary tract pathology and two of the children with no urinary tract pathology had supernumerary nipples. The odds ratio for having supernumerary nipples among the first group was 1.18 (95% Cl: 0.084-16.53, p = 0.627). Our results indicate no association between kidney and urinary tract malformations and supernumerary nipples. We believe the message to the practicing physician is that there is no need for radiographic or ultrasonographic investigation of the urinary tract in asymptomatic children found to have supernumerary nipples on routine physical examination.