A study on the resident population of 150 inhabitants of Boa Sorte in the Municipality of Corguinho, Mato Grosso do Sul State, Brazil was made, from March 1991 to March 1994, to establish the prevalence of South American Cutaneous Leishmaniasis (SACL), and to characterize the affected population, in an area of recent transmission. Twelve of the inhabitants showed lesions suspected to be SACL, and in 8 cases it was possible to confirm this by biopsy and parasitology. The mucosal form was found in one patient only, the rest showed the following cutaneous forms: ulcerated (3), ulcero-verrucose (1), hyperkeratotic ulcer (1), infiltrated maccule (1), nodule with florid regional adenopathy (1). All patients reacted favorably to treatment with glucantime, with lesion scarring. Side-effects were rare. The parasite isolated from all patients was identified as Leishmania (Viannia) braziliensis. The Montenegro skin test, applied to the 150 inhabitants, showed 32 reactive ones. Of these, six were carriers of the disease, 21 showed sequelae suggestive of the disease and five showed no signs of infection. The age grouping of the cohort ranged from 22 to 78 years, 75% being male. To date, transmission is suspected to be in the peridomicile.