The follicular lymphomas are the most common subtype of indolent non-Hodgkin's lymphoma in adults, with approximately 20,000 new cases annually in the United States, most of which are disseminated at diagnosis. Despite far-advanced stage, frequently including the bone marrow, median life expectancy is relatively long compared with other common subtypes of lymphoma, falling within the range of 7 to 10 years. Follicular low-grade lymphomas respond very well to most therapeutic interventions. Overall response rates are generally above 90%, but complete response rates are quite variable, often reflecting the duration rather than the intensity of treatment. Unfortunately, the clinical course is usually characterized by multiple remissions and relapses, even after complete remissions. Regardless of the initial treatment chosen, most patients eventually die of the lymphoma. Multiple attempts have been made over the past two decades to improve the survival for patients with follicular lymphomas, and a large number of phase III trials have been reported. These have included a variety of different therapeutic interventions, such as combination chemotherapy, recombinant interferons, new cytotoxic drugs, and immunologic agents. Although some results suggest differential benefits in selected groups of patients, most studies have not demonstrated that the use of a particular therapy convincingly prolongs survival.