The marginal neutrophil leukocyte pool and the bone marrow neutrophil reserves were assessed in 43 patients with lymphoreticular malignancies, using epinephrine and steroid stimulation. Thirty-three patients were studied before staging, following splenectomy, before and after nodal irradiation and during remission induction chemotherapy. Ten patients in partial remission were studied after 12 month or more of chemotherapy. A neutrophil count of 1,500-2,500 cells/mm3 is not a sufficient guide for midifying the chemotherapy. The response to steroid stimulation may be a more dependable guide to evaluate the patient's potential risk for infection.