From January 1, 2013, to March 1, 2024, nine patients with hematological malignancies complicated by Gilbert's syndrome in Peking University People's Hospital underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). The patients comprised seven male and two female cases, with a median age of 38 (13-60) years old. Among them, three cases were acute myeloid leukemia, three cases were acute lymphocytic leukemia, two cases were myelodysplastic syndrome, and one case was chronic myelomonocytic leukemia. None of the patients had viral hepatitis. Of the nine cases, seven cases received the Bu-Cy+ATG regimen, while the other two cases received the TBI-Cy+ATG regimen (Bu, busulfan; Cy, cyclophosphamide; ATG, antithymocyte immunoglobulin; and TBI, total body irradiation). All patients achieved neutrophil engraftment, and eight received platelet engraftment. The median total bilirubin level was 45.4 (22.5-71.2) μmol/L before transplantation and 22.0 (18.0-37.2) μmol/L on -1d of preconditioning. The total bilirubin level on +20d after the transplantation of eight patients decreased compared with the baseline level before transplantation. Moreover, one patient had a transient increase in the total bilirubin level on +5d after transplantation, which was considered to be attributed to the toxicity of Bu. No patients were complicated by hepatic veno-occlusive disease. The median follow-up time was 739 (42-2 491) days. During the follow-up period, one patient died of recurrence, and the remaining eight patients had disease-free survival events.