Lobo's disease was diagnosed in a free-ranging male bottlenose dolphin Tursiops truncatus examined as part of a live-capture and release program conducted in Matagorda Bay, Texas, USA, during July 1992. Diagnosis was based on typical presentation of a raised skin lesion, with sub-epidermal granuloma and demonstration of typical features of the organism by light microscopy, using hematoxylin and eosin, and methenamine silver stains. This is the first instance of Lobo's disease found in a dolphin on the western coast of the Gulf of Mexico.