Fifteen American patients with Burkitt's lymphoma were treated in a clinical trial employing chemotherapy, radiotherapy, and immunotherapy. Two patients died during induction, and 13 achieved complete responses. Eight patients relapsed at a median of 11 weeks from initial treatment, and seven of these have died. The remaining patient has enjoyed a prolonged third remission following intensive chemotherapy and bone marrow autograft. Five patients remain in their first remission in excess of 1 year. The major therapeutic goal in the management of Burkitt's lymphoma is the prevention of relapse; the identification of risk factors and various strategies to achieve this goal are discussed.