A search for cutaneous leishmaniasis among dogs was conducted in several forest settlements of central Panama from 1968 to 1973. A total of 11 (3.3%) of 333 animals exained was found infected and, in 9 of these, parasites were isolated in culture and characterized as Leishmania braziliensis. Infected dogs occurred in three settlements, one of which was free of human leishmaniasis. In the latter case, infections were acquired in the nearby forest during hunting excursions. Ulcerated skin lesions primarily on the lower aspect of ears, or depigmentation and inflammation of the nostrils were manifested, with persistence as long as 45 months. The parasites did not disseminate from the lesion to viscera or other areas of the skin. The dog may serve as an incidental reservoir host of human leishmaniasis and/or a liaison of the infection between the jungle and forest settlements in the Republic of Panama.