Chromoblastomycosis (CBM) is a difficult-to-treat chronic mycosis. A correct identification of its agents is relevant since they may differ in epidemiologic aspects, clinical presentation, and treatment response. Twelve patients diagnosed with CBM at Rio de Janeiro, Brazil, were included in this study. In all patients, partial sequencing of the internal transcribed spacer region was used to identify their clinical Fonsecaea isolates. Also, in vitro antifungal susceptibility was performed by the broth microdilution method. Clinical data of patients were correlated with the obtained laboratory results. Nine patients were male and three female. Evolution time of infection ranged from two months to 32 years. According to the severity of CBM, eight patients presented the moderate form (one infected with F. pedrosoi, five with F. monophora and two with F. nubica) and four presented the severe form (three infected with F. monophora and one with F. nubica). Lesions were classified as verrucous (one patient infected with F. pedrosoi, four with F. monophora and two with F. nubica) or plaques (four patients infected with F. monophora and one with F. nubica). All but one patient, infected with F. monophora and in use of thalidomide, presented localized lesions. Three other patients were also taking immunosuppressive drugs: two using tacrolimus (one infected with F. nubica and one with F. monophora) and one, infected with F. monophora, using prednisone. Surgical approaches were applied in four patients. The other eight patients used itraconazole (ITC), as monotherapy or associated with fluconazole or terbinafine. Five of these patients also required cryosurgery and/or surgery to achieve clinical cure. Four patients presented a fast clinical improvement after the beginning of antifungal therapy and their strains presented MIC of 0.5 mg/L (n=3) and 1 mg/L (n=1) to ITC. The other four patients had a slow improvement. One was infected with a strain presenting ITC MIC of 0.5 mg/L and three infected by strains with ITC MIC of 1.0 mg/L. Despite the low number of cases, this work highlights some important aspects in the physiopathology of CBM caused by different Fonsecaea species. The absence of cerebral involvement in F. monophora infected patients suggests that neurotropism of this species is related to host conditions. Isolation of the CBM agents in culture from clinical specimens is strongly recommended to allow clinical and laboratory correlation studies in this mycosis.