There is a paucity of information regarding the factors that affect nonrelapse mortality (NRM) and overall survival among children that develop chronic graft-versus-host disease (cGVHD). We performed multivariate analyses using data from the Center for International Blood and Marrow Transplant Research to identify risk factors for NRM and survival in 1117 pediatric subjects with leukemia or myelodysplastic syndrome, transplanted from related donors, unrelated donors (URD), or unrelated cord blood between 1995 and 2004. We identified 4 variables associated with higher NRM: HLA partially matched or mismatched URD, peripheral blood cell graft, Karnofsky/Lansky score < 80 at cGVHD diagnosis, and platelets < 100 × 10(9)/L at cGVHD diagnosis. Factors associated with significantly worse survival were: age > 10 years, transplantation from HLA partially matched or mismatched URD, advanced disease at transplantation, Karnofsky/Lansky < 80; and platelets < 100 × 10(9)/L. Cumulative incidence of discontinuation of systemic immune suppression at 1, 3, and 5 years after diagnosis of cGVHD were 22% (20%-25%), 34% (31%-37%), and 37% (34%-40%), respectively. This is the largest study elucidating variables affecting outcome after diagnosis of cGVHD in pediatric allograft recipients. These variables may be useful for risk stratification, development of future clinical trials, and family counseling in children with cGVHD.