Objective To explore the feasibility and safety of cotransplantation of autologous bone marrow-derived mesenehymal stem cells (MSCs) and peripheral blood stem cells in hematological malignant diseases and to observe its effect on hematopoietic reconstruction after cotransplantation. Methods Adult human MSCs were isolated from the healthy bone marrow of the patient himself with Percoll (1. 073 g/ml) and cultured in Dulbecco's modified Eagle's medium with low glucose containing 10% AB type human serum. After conditioning regimen of high-dose chemotherapy and radiotherapy, cotransplantation of autologous bone marrow-derived MSCs and peripheral blood stem cells was done in five patients with hematological malignant diseases. Results The process of the infusion was safe and there were no adverse reactions or other toxicities related to the infustion of MSCs. The median time to achieve neutrophil counts greater than 0. 5 × 109/L was 9.4 days ( ranging from 8 to 11 days) after cotransplantation and platelet counts greater than 20 × 109/L 12. 2 days (ranging from 10 to 14 days). Conclusion Cotransplantation of autologous bone marrow-derived MSCs and peripheral blood stem cells in hematological malignant diseases is feasible and safe. The rapid hematopoietic reconstruction after cotransplantation shows that MSCs have an effect on hematopeiesis, but the mechanism is still to be investigated.