Thirty-six patients with chronic B-lymphoproliferative disorders (B-LPD) underwent reduced-intensity allogeneic transplantation (RIT) from HLA-identical related donors. Diagnoses included follicular (n = 17), mantle cell (n = 9) and small lymphocytic lymphoma (n = 2), and chronic lymphocytic leukaemia (n = 8). Median age at transplant was 51 years (range, 30-66) and time from diagnosis was 3.4 years (range, 0.3-9.5). At transplant, 28% were in CR, 36% were in PR and 36% were chemorefractory. Conditioning therapy included fludarabine and either cyclophosphamide (n = 27) or melphalan (n = 9). Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporin (CsA)/methotrexate (n = 21), CsA/mycophenolate mofetil (n = 13) or CsA alone (n = 2). Eight patients died owing to acute GVHD (n = 3), infection in association with chronic GVHD (n = 4) and intra-abdominal bleeding (n = 1). Treatment-related mortality was 8% at day 100, and 17 and 20% at one and two years, respectively. The cumulative incidence of grade II-IV acute GVHD was 58%, whereas limited and extensive chronic GVHD occurred in 25 and 56%, respectively. No patient has relapsed or progressed. At a median follow-up of 48 months, overall survival probability is 80% (95% CI, 67-93%). We confirm that RIT in chronic B-LPD can result in high and durable CR rates but with significant incidences of acute and chronic GVHD.