Background: Cutaneous leishmaniasis is an infection caused by protozoan genus leishmania the incidence rate of which has been estimated as 0.28 in every 1000 individuals in Iran. Although glucantime is commonly used to treat leishmaniasis, it has some side effects including increased liver enzymes and electrocardiogram changes. In addition, the drug is expensive, the injection is painful, and research shows that glucantime resistance of parasite is growing in different parts. Therefore, scientists are paying more attention to new drugs such as nanosilver solution. The present study tried to evaluate the in-vivo topical effects of different concentrations of nanosilver solution.Methods: Colloidal particles were used in this study. Female Balb/c rats aged 6-8 weeks were studied in groups of 10. Different concentrations [60, 80, 120, 130, and 2000 particles per million (ppm)] of nanosilver 4000 were prepared (Nano Alvand, Arad Co., Iran). Rats were subcutaneously injected at the base of the tail with 0.1 ml of solution containing the parasite. Clinical control of the infection trends was conducted weekly for 6 weeks by measuring lesion diameter at the base of the tail. Data was analyzed by paired t-test, analysis of variance (ANOVA), and Tukey test. The significance level was considered as P < 0.05.Findings: Mean lesion diameter before and after the treatment did not significantly differ between different groups (P > 0.05). Likewise, a significant difference in splenic parasite load was not observed between different treatment groups. Conclusion: Based on our results, different concentrations of nanosilver are ineffective in reducing mean sizes of lesions. However, nanosilver can be used in treating secondary infections in patients with cutaneous leishmaniasis.