We performed a computerized search on sulfadiazine-associated nephrotoxicity reported in human immunodefiency virus (HIV)-infected patients in the international literature. Including an original case report, we summarized 35 acquired immunodefiency syndrome (AIDS) patients from 1987 to 1995 in an analysis comparing their features to historical HIV-negative controls from the 1940s and 1950s. Likely due to a high prevalence of potential risk factors, incidence of sulfadiazine-associated renal impairment was 1.9%-7.5% in AIDS patients and 1%-4% in HIV-negative controls. Its occurrence appeared to be delayed in HIV-infected patients with a median of about 3 weeks of medication compared with about 10 days in HIV-negative subjects. Correspondingly, the cumulative sulfadiazine dose at manifestation doubled in AIDS patients with a median of 84 g versus 40 g in controls. Patients usually presented with flank or lumbar pain, oliguria, and (macro) hematuria. Urinalysis showed typical "sheaves of wheat" crystalluria, erythrozyturia, and, less commonly, leukozyturia and proteinuria. Echogenic (mostly peripelvic) densities, renal stones, and hydronephrosis are frequent findings on ultrasound examination, whereas X-ray examination possesses a low diagnostic sensitivity. The principle aim of therapy in these patients is to (re)institute the physicochemical urinary solubility of sulfadiazine and its metabolites. For this purpose, forced rehydration and, most importantly, urine alkalinization proved to be effective measures without an absolute need to withhold the drug. Provided prophylactic and therapeutic recommendations are complied with, outcome of this drug-related side effect is usually excellent, and rare relapses will similarly respond well.