Histocompatible hematopoietic stem cell transplantation (HSCT) was conducted on a 4.5-year-old girl with Niemann-Pick disease type B. The donor was her unaffected brother. At the time of transplantation, she had severe pulmonary disease. After her first HSCT, she developed graft failure. Five years after her second HSCT, her sphingomyelinase levels are within normal levels, she has no pulmonary symptoms, and aside from persistent graft versus host disease, she is doing well.