Purpose: To review the current literature as it pertains to hemorrhagic cystitis (HC) in the pediatric bone-marrow transplant (BMT) population. By reviewing the pathophysiology of the disease, preventive methods, and therapeutic options, urologists may be better equipped to manage this challenging clinical scenario. Materials and methods: The HC literature was reviewed using a MEDLINE/PubMed literature search, specifically focusing on the pediatric BMT population as it pertains to the incidence, pathophysiology, prevention, and treatment of HC. Results: Conservative estimates of HC incidence in recent retrospective studies of pediatric BMT populations still approach 10-20%. Several high-volume pediatric BMT centers have reported contemporary data on their experience with HC providing increased insight into incidence and pathophysiology. Accumulating evidence linking BK virus to HC is a significant development warranting further investigation. Other contributing agents/risk factors need identification in the likely multifactorial etiology of HC. Preventive and therapeutic strategies have made modest advances, but certainly need further validation with prospective randomized studies. Conclusions: Pediatric BMT patients are susceptible for HC development despite preventive measures and improved insight into the pathophysiology. Unfortunately, there are no evidence-based treatment guidelines for this difficult clinical issue that frequently requires prolonged care and multiple treatment modalities necessitating judicious patience in the application of more aggressive interventions. (C) 2009 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.