In this study peripheral blood natural killer (NK) cell activity was evaluated in 17 pediatric cases with Hodgkin disease (HD) (9 untreated, 8 in remission) and 20 age-matched healthy children. Peripheral blood CD16 and CD56 molecule expressions were also examined. No difference related to NK cell numbers and cytotoxic activity was detected at either stage of the disease. In cases in which long-term remission has been achieved (> or = 5 years) NK cell activity was slightly but not significantly increased in parallel with remission duration. Finally, no relation between NK cell activity and the etiology, prognosis, and severity of the disease has been established in children with HD.