Miltefosine (2.5 mg/kg/day for 28 days) was investigated for treatment of New World cutaneous leishmaniasis in Colombia and Guatemala. The data from a controlled study was remarkably similar to the data of a prior uncontrolled pilot study. In the controlled study, the per-protocol 6-month cure rate for Leishmania panamensis disease was 91% compared with a concomitant placebo cure rate of 38%. In Guatemala, the cure rate for L. braziliensis and L. mexicana disease was approximately 50% compared with approximately 20% for placebo. In both countries, nausea but not 'motion sickness' and vomiting but not diarrhoea were experienced by approximately 30% more miltefosine patients than placebo patients. Mild elevation of creatinine, but not of aspartate aminotransferase or alanine aminotransferase, was also more frequently seen in the miltefosine group than in the placebo group. Miltefosine was well tolerated, and as effective as historic values of antimony for treatment of L. panamensis disease.