Twenty-one patients with alkylator-resistant plasmacell neoplasms were treated with Peptichemio (PTC) at a dose of 40 mg/m2 for 3 days every 3 weeks or, in the case of persistent leukopenia and/or thrombocytopenia, at the single dose of 70 mg/m2 every 2-3 weeks according to haematological recovery. Seventeen patients, 10 with multiple myeloma and seven with extramedullary plasmacytoma (EMP), were fully evaluable. Six of 17 patients (35%) responded: three of seven EMP patients had a complete remission and 3 of 10 multiple myeloma patients had an objective response greater than 50%. The median duration of response was 8.5 months. An EMP patient obtained a complete response lasting for 16 months. The most frequent toxic effect were phlebosclerosis, occurring in all the patients, and myelosuppression, which was severe in only one case. PTC appears to be an active drug in patients with plasmacell neoplasms even if resistant to alkylating agents.