In Bolivia, potato (Solanum tuberosum L.) leaf spot diseases have traditionally been regarded as of Little importance especially in the Andean highlands. In recent years, however, new types of leaf spot disease have appeared, their distribution widened, and their incidence and severity increased. The present work identifies the main types of leaf spot present in the traditional highland growing regions of the Departments of La Paz (around 4350 m) and Cochabamba (2900-4100 m), and in the north of the Department of Santa Cruz, the new lowland área of potato production (around 235 m). Five causal agents were identified in the highland region: Alternaria solani, Septoria lycopersici, Cercospora solanicola, Passalora concors and Botrytis cinerea. These affected several types of native potato. In the lowland region, A. solani and Stagonospora spp. were found to cause leaf spot disease on cv. Desireé. In both agroecosystems, the diseases sometimes appeared alongside late blight (caused by Phytophthora infestans). The leaf spot disease caused by A. solani, was very destructive, while that caused by S. lycopersici was only destructive in the highlands.