Fifty-two patients with refractory lymphoma were prospectively treated with prophylactic T lymphocyte infusion after T cell-depleted allogeneic bone marrow transplantation, to induce graft-versus-lymphoma effect. Thirty-three patients had related donors; 19 had unrelated donors. After transplantation with marrow that had 0.8 +/- 0.4 x 10(5)CD3(+) cells/kg, T cells up to 1.75 x 10(6) CD3(+) cells/kg were given over 3 months provided > or = grade II acute graft-versus-host disease (GVHD) was not seen. The cumulative incidence of grades II-IV acute GVHD was 69%. Twenty of 32 evaluable patients (63%) developed chronic GVHD. Ten patients (19%) died of GVHD. The Kaplan-Meier 5-year overall survival of all patients was 34%. On multivariate analyses, chronic GVHD was significant for relapse (hazard ratio of 1.7, P < 0.05), and for overall survival (hazard ratio 1.4, P < 0.001). Chemosensitivity was significant for relapse only on univariate analysis. Patients who developed chronic GVHD had 4 years median survival, compared with 9 months in patients without chronic GVHD, P < 0.001. The study shows that patients with chronic GVHD have superior survivals, most probably related to a graft-versus-lymphoma effect, which could be modulated by prophylactic T cell infusion.