Background: Some researchers claim that permethrin-impregnated clothes are effective in the prevention of cutaneous leishmaniasis. Objectives: To determine the effectiveness of permethrin-impregnated clothes in the prevention of cutaneous leishmaniasis. Patients and Methods: 272 soldiers were randomized in two groups. In one group permethrin-impregnated clothes and in the other group, control clothes were used. In each group the clothes were worn during days and nights for three months and the soldiers were followed for additional 6 months. Results: 9 (6.5%) of 138 soldiers wearing control clothes and 6 (4.4%) of 134 soldiers wearing permethrin-impregnated clothes acquired cutaneous leishmaniasis. The difference between two groups was not statistically significant. Conclusion: Permethrin-impregnated clothes are not effective in the prevention of cutaneous leishmaniasis.