The authors report five cases of acute granular leukemia which complicated the course of multiple myeloma treated by chemotherapy. They then review the literature, and discuss 30 cases which they found. The important point clinically is the long duration of the course (average 56 months) in multiple myeloma complicated by acute granular leukemia. Usually chemotherapy permitted a good quality remission and when the leukemia develops there is no longer any trace of myeloma. The mechanisms of onset of this type of leukemia during myeloma are discussed. They are probably complex and various but there is no doubt concerning the responsability of chemotherapy and in particular alkylating agents.