Fifty-three consecutive cases of adult CD30+ anaplastic large cell lymphoma (ALCL) have been analyzed. Thirty-six were classified as Hodgkin's disease like variety (HL) (67%) and seventeen as so-called common type (CT) (33%). All cases strongly expressed the CD30/Ki-1 antigen; the neoplastic cells expressed CD15, CD45 and EMA in 60%, 44% and 33% of cases, respectively; T. B and null phenotypes were found in 37%, 17% and 46% of cases. Bulky mediastinal, B symptoms, and extranodal disease at diagnosis were present in 36%, 49% and 25% of cases. EBV encoded latent membrane protein (LMP-1) was found in 10 cases. Of the 13 tested cases only 4 expressed a weak positivity of the CD40 molecule, in a fraction of the tumor cells; in the same cases CD21 was never found. Patients were treated with various protocols; of the 50 evaluable patients, 39 (78%) obtained a complete remission (CR), 3 (6%) a partial remission (PR) and 8 (16%) did not respond. The projected overall disease free survival (DFS) at 36 months is 70%. Only patients with advanced disease stage (III-IV) showed a statistically decreased DFS and survival. Only symptomatic and extranodal disease significantly appeared to influence survival. This study confirms the good outcome of this group of lymphomas and differs from other reports for some clinical (lower percentage of advanced stage, extranodal disease and skin infiltration) and pathological (HL/CT ratio and immunophenotype) features.