With limited options to treat cutaneous leishmaniasis, constant monitoring of the rate of resistance to pentavalent antimony-based drugs is needed. This study identified the infecting Leishmania species and evaluated the results of meglumine antimoniate (Glucantime®) therapy in a new focus of cutaneous leishmaniasis in Birjand, eastern Islamic Republic of Iran. Smears from 150 patients showed that 141 patients were infected by L. tropica and 9 by L. major. In total, 141 patients with L. tropica infection completed Glucantime® treatment and follow-up; 63.8% were treated intralesionally and 36.2% by intramuscular administration. The overall success rate after one course of therapy with Glucantime® was 96.5% (136/141), and all the failures (5/141) occurred with intramuscular injections. Statistical analysis showed a significant difference between the failure rates of intramuscular and intralesional injections. Children < 10 years old had a significantly higher failure rate than adults.