Visceral leishmaniasis is endemic in southern Saudi Arabia. We prospectively evaluated 121 patients with visceral leishmaniasis at King Fahad Hospital in Gizan. All patients were infants and children. Seasonal variation was observed with more cases presenting in late spring and summer and few in winter. The predominant clinical features in these patients were chronic fever, abdominal distention, weight loss and hepatosplenomegaly. Lymphadenopathy was rare in contrast to African kala-azar. Common laboratory abnormalities included anemia, leukopenia, thrombocytopenia, hypoalbuminemia and hypergammaglobulinemia. Liver function tests were deranged in one-third of patients. Leishmania hemagglutination test was positive in all patients and all of them had positive bone marrow smear or culture for Leishmania donovani. Patients responded well to stibogluconate (Pentostam) therapy with a cure rate of 96.7%. Four patients died in the first few days of therapy. Jaundice and grossly deranged liver function tests were found to be bad prognostic signs.