Vinblastine sulfate therapy and cyclophosphamide therapy were compared in a random fashion in 69 patients with various types of lymphoma in a total of 96 courses of therapy. High initial or "loading" doses were not used and dosage was adjusted at weekly visits according to effect and toxicity. Vinblastine, to which 28 of 33 patients responded, was found to have marked superiority over cyclophosphamide in the control of Hodgkin's disease. However, cyclophosphamide was superior for the therapy of reticulum cell sarcoma and lymphosarcoma, with a response appearing in 12 of 20 patients with these diseases. Toxicity was not a serious problem in these cases. Vinblastine is recommended as the initial chemotherapeutic agent in patients with Hodgkin's disease, unless a prompt response is necessary.