Thirty adult patients with CMML were evaluated to determine prognostic factors that might have an impact on conversion to acute leukemia and survival. Neither leukocyte count nor monocyte count correlated with survival. The median survival for all 30 cases was 41 months. Patients with less than 5% marrow blasts had a median survival of 60 months but those with 5-20% blasts had only a 9-month median survival.