Three patients with B-prolymphocytic variant of HCL (HCL-V) were treated with a chlorinated purine analogue, 2-chlorodeoxyadenosine, at a daily dosage of 0.12 mg/kg in 2-hour intravenous infusion for 5 consecutive days. Partial remission was achieved in only 1 patient, who relapsed after 6 months. Two other patients did not respond to the treatment. HCL-V is a distinct clinicopathological entity which seems to be resistant to various therapeutic modalities. However, further observations are necessary in order to establish the efficacy of 2-CdA in the treatment of HCL-V.