Piponulfan is neutral, difunctional alkylating derivative of piperazine. This agent was studied for their antineoplastic activity. Piposulfan has been found to be active against the following mouse tumors: sarcoma 180, carcinoma 755, and leukemia 1210. In patients with polycythemia piposulfan produced a response rate similar to that seen with pipobroman, busulfan, and triethylene melamine. However, piposulfan produces noticeably less toxicity than standard recommended doses of either busulfan or triethylene melamine. Various degrees of therapeutie remissions were seen in patients with malignant lymphomas, acute and chronic leukemia, multiple myeloma, adenocarcinomas, epidermoid carcinomas, and various types of sarcomas. The most common adverse reactions to piposulfan involved the hematopoietic (bone marrow depression) and gastrointestinal organs.