Twenty four patients with angio-immunoblastic lymphadenopathy (AILD) presenting between 1974 and 1985 have been reviewed. Clinical features at presentation included rash, fever, lymphadenopathy and hepatosplenomegaly in 75% of patients. Polyclonal hypergammaglobulinaemia was seen in 19/20 patients; 5 had normal immunoglobulin levels. Combination chemotherapy with MVPP was the optimal treatment with 6/7 patients achieving complete remission. Duration of remission ranged from 9 months to 4 years and was significantly longer in patients achieving complete as opposed to partial remission. In 6 patients phenotype studies were performed on single cell suspensions and immunoperoxidase studies on frozen sections of 7 lymph nodes. There was a reversal of the normal T suppressor/helper cell ratio with a predominance of T suppressor cells. Loss of normal B follicles was observed histologically in all except one lymph node. Germline configuration of the beta B-chain of the T cell receptor was observed in lymph nodes of 4 patients with AILD, and a rearranged T cell receptor was observed in 1 patient in whom a second lymph node biopsy had shown alteration of the histological picture to that of T-zone lymphoma. Frozen sera of 15 patients were screened for antibodies to HTLV I and III and were found to be negative.