Between 1970 and 1986 61 patients with large cleaved cell lymphoma (LCCL) were observed and treated. Median age was 56, and there were slightly more women than men (ratio, 1.4:1). Forty-four cases (72%) had both a nodular and diffuse pattern; eight cases were nodular; nine cases were diffuse. Forty-three patients (70%) had Stage III or IV disease; four patients were Stage I (7%); 14 were Stage II (23%). Bone marrow was involved in 15 of 56 evaluable patients (27%). The median survival was 57 months. It was significantly shorter in symptomatic patients (median, 20 months) than in asymptomatic patients (median, 66 months; P = 0.002). Survival time was also shorter in Stage III and IV patients (median, 46 months) compared with Stage I and II patients (median, 100+ months; P = 0.032). Survival was independent of the disease pattern, marrow involvement, age, gender, and surface immunoglobulin heavy or light chain. Among Stage III and IV patients, survival was the same in patients who received therapy initially and in those who were treated expectantly. Among 10 advanced-stage patients who did not initially receive therapy, the median time to beginning therapy was 17 months; five patients received no therapy for 40 to 96 months. Among 14 advanced-stage patients receiving therapy regarded as curative in aggressive lymphoma, 50% experienced a complete remission (CR). However, unlike other aggressive large cell lymphomas, long-term, relapse-free survival was observed in only 9% of patients as the majority of CRs were associated with relapse rather than cure. Despite the fact that it is a large cell lymphoma, LCCL is best regarded as an indolent lymphoma.