AbstractT‐cell subsets were determined by the Leu monoclonal antibodies in the peripheral blood and/or bone marrow of 52 patients with B‐cell chronic lymphocytic leukemia (B‐CLL) not on therapy at the time of study. The diagnosis of B‐CLL required that the leukemic cells expressed surface receptors for “la‐like” antigen, Fc fragment of IgG, mouse red blood cells (MRBC), C3‐coated red cells (EAC), and low density of monoclonal surface immunoglobulin. The Leu‐3a+/2a+ratio was applied to define the balance between the helper/suppressor subsets in the residual T‐lymphocytes. Most patients showed a decrease in the Leu‐3a+/2a+ratios at all stages of disease. The decrease in ratio was mainly related to a decrease in the Leu‐3a+T‐cell subset. The more advanced stages of B‐CLL were associated with lower Leu‐3a+/2a+ratio, higher total white cell and percent lymphocyte counts. There was no correlation between the proportion of EAC or MRBC rosetting cells and stages of B‐CLL. This analysis further suggests that B‐CLL is an immunosuppressed state that becomes more pronounced in the advanced stages and is characterized by a progressive decrease in