The article describes the transplantation of hematopoietic stem cells (HSC) in children with severe form of mucopolysaccharidosis type I – Hurler syndrome. This method is recommended for the patients under 2.5 years with a high rate of psychomotor development. According to clinical guidelines, HSC is performed according to traditional high-dose, chemotherapy-based conditioning regimens which provide intense immunosuppression to prevent graft rejection. Currently, it is recommended to use a reduced-intensity conditioning mode. An international multicenter study assessed the long-term outcome in patients with Hurler syndrome and confirmed improvements in life quality and expectancy.