Agents of human chromoblastomycosis, a skin disease almost exclusively caused by members of the order Chaetothyriales, are assumed to be traumatically inoculated into the skin with sharp environmental materials such as plant thorns or wooden splinters carrying the respective opportunist. In the supposition that such fungi should have their main habitat in the environment, we investigated the occurrence of black fungi in living areas of patients with chromoblastomycosis. In South America Fonsecaea agents are prevalent as agents of the disease, while also related Cladophialophora species, known from other types of skin infections, are known from the continent. To assess population diversities among clinical and environmental strains of fungi in the genus Fonsecaea, we applied sequences of the Internal Transcribed Spacer Regions and the Partial cell division cycle, ��-tubulin, Elongation factor and Actin genes. Some species of the Fonsecaea genus cause human chromoblastomycosis. In order to elucidate chromoblastomycosis epidemiology, environmental origin and virulence of the disease agents we are using molecular markers and transcriptome and genome sequencing. In addition, we are evaluating the virulence of these agents through in vitro virulence tests using animal and plant models. Strains originated from sampling of clinical and environmental sources from several regions of Brazil were included in this study