SummaryThe effect of a new piperazine derivative, piposulfan or Ancyte, was studied in 21 patients suffering from leukemias and malignant lymphomas and in 51 patients with solid tumors.Remissions were observed in about 50 % of the cases of Hodgkin’s disease, effects also were observed in polycythemia vera and in chronic myeloid leukemia.A remission of 15 months was obtained in one case of breast cancer resistant to androgens and estrogens.Other cases did not respond to treatment.Blood toxicity was moderate and, in most cases, reversible. The mean daily dose should not exceed 140 mg.