The role of early splenectomy in the management of chronic myeloid leukemia (CML) was investigated in a multicentric study with 21 contributing Hospitals. One hundred eighty‐nine patients younger than 66 years of age and previously untreated, were first seen between November 1974 and May 1977, were randomized to splenectomy or to nonsplenectomy, were given the same chemotherapy (busulfan, and courses of arabinosyl cytosine, 6‐thioguanine, and daunomycin), and were followed up for more than 5 years. Median survival was 45 months. No relationship of splenectomy to survival length could be shown either in the whole series, or in several subgroups that were selected according to presentation features and stage classification. Thromboembolic and vascular accidents were more frequent in the splenectomy group, and this was associated with more difficult control of platelet count. Early splenectomy is not recommended for treatment of CML.