Thrombotic thrombocytopenic purpura (TTP) during infectious diseases is a known, but rare event. In this paper a case of TTP associated with primary infection by Mycobacterium tuberculosis is described. Various therapeutic approaches were used with the patient: fresh frozen plasma infusions and plasma exchange, specific anti-tuberculous therapy, anti-platelet drugs and steroids. A complete remission occurred 3 months after the onset of the acute disease. A hypothesis on the pathogenesis of TTP might be an increased pro-coagulant activity of interleukin 1 (IL-1) on endothelial cells.