An open trial of liposomal amphotericin B (AmBisome [L-AmB]; Vestar, San Dimas, CA) for treatment of complicated visceral leishmaniasis was performed in Sudan. Forty-nine patients were treated, and there were six deaths (12% mortality); these were not attributed to therapy. Thirty-seven patients were selected for the trial because of (1) relapse after treatment with a combination of pentavalent antimony (Sbv) and aminosidine, (2) incomplete parasitological response to Sbv and aminosidine, or (3) severe illness. Drug regimen 1 (3 doses of 3-5 mg/kg, on days 0, 3, and 10) cured 8 (50%) of 16 patients; regimen 2 (6 doses of 3-5 mg/kg, on days 0, 3, 6, 8, 10, and 13) cured 14 (88%) of 16. For four of 10 partial responders, "rescue" therapy with L-AmB alone (3 mg/kg daily for 10 days) resulted in cure. Twelve less-unwell patients received regimen 3 (4 doses of 4-5 mg/kg, on days 0, 2, 5, and 7); seven of 11 patients evaluated (64%) were cured. The optimal regimen of L-AmB in these circumstances is administration of 4 mg/kg on days 0, 3, 6, 8, 10, and 13.