Abstract. Eight patients with idiopathic thrombocytopenic purpura (ITP), who were refractory to glucocor ticoid therapy, were given slow infusions of vincristine (VCR) over a 4-to 6-hour period at weekly intervals for 4 weeks. Three patients showed a return to normal platelet counts maintained for 3 months or longer. A tran sient recovery was observed in 1 patient and a partial response was observed in 3 patients. All patients tolerated therapy well, without side effects. In conclusion, therapy with slow infusion of VCR can be effective in refrac tory ITP.