Allogeneic hematopoietic stem cell transplantation (HSCT) is a therapeutic approach for malignant and nonmalignant hematological disorders. Survival rates increased after allogeneic HSCT, and therefore, late transplant-related complications have become more frequent. We retrospectively analyzed the incidence, risk factors, and outcome of obliterative bronchiolitis. Between January 2000 and November 2012, 89 transplanted pediatric patients were retrospectively evaluated. The diagnosis of bronchiolitis obliterans was made according to the NIH consensus criteria for chronic graft-versus-host disease (cGVHD). Univariate and multivariate analysis was conducted on the following risk factors: age at HSCT, sex, high risk, type of donor and type of diagnosis, conditioning regimen, total body irradiation, busulfan-based regimen, acute and cGVHD, donor sources, ABO blood group incompatibility, Rh incompatibility, human leukocyte antigen (HLA), and cytomegalovirus (CMV) reactivation. Seven patients met the diagnostic criteria. The prevalence was 7.8%. Pulmonary function tests (PFTs) performed in all bronchiolitis obliterans (BO) patients did not present any abnormality. PFT variables decreased significantly. Four patients presented with moderate forms of obliterative bronchiolitis, 1 patient was identified as having mild form, and 2 patients were categorized with severe obliterative bronchiolitis. cGVHD, both in hepatic and cutaneous form, was demonstrated in the present study to be a major risk factor. The higher incidence of bronchiolitis obliterans in children with hepatic and cutaneous GVHD could be potentially interpreted on the basis that cGVHD is an immunoregulatory disorder that involves almost any organ of the body, and therefore, BO could be described as the pulmonary manifestation of a systemic disease.