Rubidazone was used as sole chemotherapy in 170 adults and children with acute leukemia and sarcoma. When rubidazone was employed to treat the first attack, complete remission was achieved in : 1) 40 out of 70 patients (57%) with AML; 2) two out of six patients with AML where previous chemotherapy had failed; 3) four out of five patients with ALL; 4) 12 out of 14 patients with acute monoblastic leukemia. When used to treat relapse, rubidazone produced complete remission in : 1) 14 out of 31 cases of AML; 2) 18 out of 39 cases of ALL; 3) 2 out of 3 cases of non-Hodgkin lymphoma. Treatment of a case of rhabdomyosarcoma was unsuccessful. In the treatment of acute myeloblastic and monoblastic leukemias, it may be concluded that rubidazone induces a higher rate of complete remission than any other previously reported drug which was used alone. It also achieves remission rates similar to those resulting from a combination of daunorubicin and Ara-C. Furthermore, when compared with daunorubicin, rubidazone allows better control of the induction of aplasia.