In August 1997, AmBisome (liposomal amphotericin B, Nexstar, San Dimas, CA) was the first drug approved for the treatment of visceral leishmaniasis by the U.S. Food and Drug Administration. The growing recognition of emerging and reemerging infections warrants that safe and effective agents to treat such infections be readily available in the United States. The following discussion of the data submitted in support of the New Drug Application for AmBisome for the treatment of visceral leishmaniasis shows the breadth of data from clinical trials that can be appropriate to support approval for drugs to treat tropical diseases.