The aging kidney is at risk for both toxic and hemodynamic-induced acute damage, resulting in a high incidence of acute renal failure (ARF) in elderly patients. The effect of age and or gender in ARF mortality in African Americans (AA) was studied in a 3-year, computer assisted retrospective review. In an inner city medical center, 100 patients classified as ARF at discharge or expiration were included in the study. Patients were classified into 3 age categories: <40, 40-64, and >64 years. The incidence of ARF was 35%, 28% and 37%, respectively. Patients >64 years of age were less likely to be dialyzed. Both pre- and postrenal causes of ARF were more common in patients >64 years of age than in younger patients. Hospital length of stay increased progressively with age. Mortality was lower in patients >64 years of age than in younger patients. The incidence of ARF was higher in male than female patients and the incidence of sepsis was higher in female than male patients. Dialytic need was greater in male patients, but mortality was higher in female than male patients. Multivariate logistic regression showed that in the presence of sepsis, oliguria and mechanical ventilatory support, the relative risk of mortality associated with advanced age was 16.5, the relative risk of mortality associated with female gender was 0.2. In summary, hospitalized elderly African-American patients have a high incidence of ARF, and patients less than 40 years of age are equally at risk. Although mortality was higher in female patients, gender and advanced age did not independently contribute to high mortality. Neither age nor gender considerations should supplant sound clinical judgment in the management of and decision making in elderly African-American patients with ARF.