The kidneys in patients with acquired immunodeficiency syndrome (AIDS) are subject to a variety of insults. Renal manifestations can be seen with imaging studies of AIDS patients. Computed tomographic (CT) and ultrasound (US) scans of 64 patients with AIDS and renal dysfunction were retrospectively reviewed and compared with clinical, laboratory, and, when available, biopsy results. Imaging abnormalities included increased cortical echogenicity, nephromegaly, pyelonephritis, lobar nephronia, focal masses caused by abscess and lymphoma, parenchymal calcification, hydronephrosis, and infarct. Generally, patients with AIDS as a result of intravenous drug abuse and those with multiple risk factors were more likely to have abnormalities demonstrated at imaging as well as poorer prognosis than were patients in the homosexual transmission group in this series. Although US should be the screening study used in patients with AIDS and suspected renal dysfunction, CT and magnetic resonance imaging may be necessary to identify focal infectious, ischemic, and neoplastic processes.