We analyzed the clinical outcome in 90 children undergoing allogeneic PBSC transplantation from HLA-identical relative for leukemia. GvHD prophylaxis was CsA+ methotrexate in 50 and CsA+/-steroids in 40. Median CD34+ cells infused were 6 x 10(6)/kg (range, 1.4-32). Median follow-up was 60 months (range, 6-115). CI of transplant-related mortality (TRM) was 18.4+/-4%. On multivariate analysis, high Lansky score (>80) at transplantation was associated with lower TRM (HR, 0.9; P<0.0002). Relapse incidence (RI) was 33.6+/-6%. On multivariate analysis, high Lansky score at transplantation and cGvHD were associated with lower RI (HR, 0.04; P<0.0005 and HR, 0.23; P<0.03, respectively). Disease-free survival (DFS) was 57.8+/-5%. Disease status at transplantation (HR, 0.33; P<0.02), steroid treatment at day +90 (HR, 5.61; P<0.005) and cGvHD (HR, 0.23; P<0.005) had a significant impact on DFS in multivariate analysis. CI of cGvHD was 63.7+/-7%. Patients with cGvHD had better DFS (65+/-5%) because of lower RI (15.7+/-6%) and similar TRM (27.4+/-4%). These data suggest acceptable long-term outcomes after allogeneic PBSC transplantation in children despite the high incidence of cGvHD. These patients had a lower risk of relapse and a better DFS.