Background: Cutaneous leishmaniasis is a common parasitic disease in Isfahan province. A common complication of cutaneous leishmaniasis is bacterial superinfection, which may intensify the disease and produce scarring. Objective: The aim of this study was to determine the bacterial species isolated from infected lesions of cutaneous leishmaniasis. Patients and Methods: Two hundred out of 874 patients with cutaneous leishmaniasis referred to Dermatology and Leishmaniasis Research Center in Amin Hospital in Isfahan during four months (September to December 1999) who had signs of bacterial superinfection were studied by taking microbial cultures from their lesions. Results: Bacterial cultures were positive in 177 cases (20.7% of all patients and 88.5% of sample patients). The isolated bacterias included S.aureus in 61.5%, S.epidermidis in 20.5%, E.coli in 3.5%, proteus vulgaris in 1.5% and Klebsiella in 1.5%. Eighty seven percent of infected patients had ulcerative nodules. Bacterial super infection was significantly more common in ulcerated lesions than non-ulcerated ones (P=0.00001).