Visceral leishmaniasis is an endemic disease caused by various species of Leishmania. We made a retrospective study of 57 consecutive patients with visceral leishmaniasis in Brazil. Patients with visceral leishmaniasis were identified using the registries of the São José Infectious Diseases Hospital. The sample was divided into two groups: patients with serum creatinine (Scr) <1.3mg/dL and Scr > or = 1.3mg/dL. We compared these two groups for differences in clinical manifestations and laboratory features. Patients' mean age was 28 +/- 18 years old; 74% were male. The main clinical symptoms and signs presented in the initial evaluation were: fever (97%), splenomegaly (96.4%), weight loss (95.5%), pallor (93.6%), cough (89.7%), hepatomegaly (87.2%), asthenia (83.3%), anorexia (82.9%) and vomiting (73.9%). Acute renal failure was found in 15 patients (26.3%) and eight of these patients had ARF before amphotericin B administration. The mean age was higher in the group with Scr > or =1.3mg/dL. Death occurred in three cases; all deaths occurred with Scr > or =1.3mg/dL. There were no significant differences in the frequencies of the clinical symptoms and signs between the two groups. The laboratory data and demographic characteristics were significantly worse in the Scr > or =1.3mg/dL group. Renal dysfunction is an important feature of this disease; it is associated with important morbidity and can increase mortality.