We retrospectively evaluated the incidence, risk factors for chronic graft-versus-host disease (cGvHD) and outcome in 80 pediatric patients (36 male) (median age 13 years) who underwent allogeneic peripheral blood progenitor cell transplantation. Patients were grafted from an HLA-identical sibling after myeloablative conditioning (total body irradiation (TBI) based 52; non-TBI 28). GvHD prophylaxis used were: cyclosporin A (CsA)+ short methotrexate (MTX) in 52 and CsA+/-prednisone in 28. The median number of CD34+ cells infused were 5.8 x 10(6)/kg (range: 1.4-32.8). The median follow-up was 24 months (range: 3-94). In all, 28 patients had cGvHD (confidence interval (CI): 54.2+/-10%). Factors that were significant on univariate analysis were diagnosis (P=0.03) and GvHD prophylaxis administered (P=0.04). On multivariate analysis, only GvHD prophylaxis used was associated with a significant risk of cGvHD (hazard ratio (HR): 3.94; 95% CI: 1.41-10.91, P=0.009). The CI of cGvHD for patients receiving CsA+MTX was 40.9+/-12 vs 76.5+/-18% for patients who did not (P=0.03). The probability of relapse was 36+/-6% for all patients (12.5+/-8% for patients with cGvHD vs 47.9+/-8% without cGvHD). The probability of disease-free survival was better for patients with cGvHD (69.9+/-10 vs 37.9+/-7%; HR: 3.59, 95% CI: 1.47-5.56; P=0.001). Our data suggest that the GvHD prophylaxis used is the most relevant predictor of cGvHD. Patients with cGvHD had a lower risk of relapse and a better survival.