Nine patients with recurrent glioblastoma were given autologous adherent lymphokine-activated killer (A-LAK) cells and interleukin-2 (IL-2) administered directly into the tumor cavity through an Ommaya tube placed during surgery/biopsy. The immunotherapy was well tolerated and the response rate was 33% (one complete response, two partial responses, four with stable disease and two with progressive disease). However, survival 18 months from initial diagnosis did not differ from that reported in the literature for patients treated conventionally. Serial determinations of IL-2 in the tumor cavity during the course of treatment revealed that IL-2 concentrations were sufficient to maintain lymphocyte activation. Since steroid medication was discontinued during treatment and A-LAK cells have greater antitumor activity than standard LAK cells, other factors are discussed that might explain the limited results.