Thrombotic thrombocytopenic purpura (TTP) is a rare disorder characterized by microangiopathic haemolytic anemia, consumption thrombocytopenia, renal impairment, neurological dysfunction, and fever, but all these features are not present in every patient. Although the prognosis of TTP has improved since it was demonstrated that large volumes of fresh frozen plasma (FFP) lead to a remission in most patients, the disease remains fatal in many instances. Therefore, other therapies are often used in TTP, but there is skepticism about their value, since such treatments are often used in combination, making evaluation difficult. This report describes three patients with TTP and a consistent therapeutic response occurring 5 days after vincristine in each of four instances.