Two patients were mistakenly treated for several months for tuberculosis. Both had lung and vertebral involvement and one patient had superficial skin lesions as well. Blastomycosis was eventually confirmed by fungal culture, but only after both patients had deteriorated markedly; one died soon after treatment with amphotericin B was started. In Africa, blastomycosis is a relatively rare condition which can mimic tuberculosis; it is one of several infections which should be borne in mind when dealing with apparently non-responsive tuberculosis.