From August 1979 to April 1981, 33 consecutive patients with malignant hematological diseases, entered this phase II study. Sixteen patients had NHL, eight CLL, four Myeloma, three HD, one ALL, and one Polycythaemia vera. Two patients were unevaluable because of early death. The median age was 67 years. Eight patients were not pretreated with drugs. Two CR (5+, 20+ weeks) were obtained among NHL patients, whereas five PR were observed among two NHL, one CLL, one Myeloma, and one HD patients, respectively. Toxicity was almost exclusively hematologic and occurred in ten patients, in one of them causing severe myelosuppression. Moreover, severe asthenia, attributable to VM26, was encountered in three patients, in one requiring the suspension of the treatment.