Osteogenic growth peptide (OGP) increases blood and bone marrow cellularity in mice, and enhances engraftment of bone marrow transplant. Carboxy-terminal pentapeptide (OGP10-14) holds several properties of full-length polypeptide. We evaluated whether synthetic OGP-derived pentapeptide (sOGP10-14) has some activity on peripheral blood cell recovery after cyclophosphamide-induced aplasia, and on stem cell mobilization. Peripheral blood stem cell (PBSC) mobilization was evaluated by administering granulocyte-colony stimulating factor (G-CSF) or sOGP10-14 after cyclophosphamide (CTX) injection. Haematological parameters and CD34/Sca-1 positive cells were sequentially evaluated. Colony-forming tests were performed in bone marrow cells from CTX-, G-CSF- and sOGP10-14-treated mice. sOGP10-14 was able to enhance band cells and monocyte recovery after cyclophosphamide administration. White blood cell (WBC) counts reached the maximum peak by day +10 but, on day +7, a significant recovery was already detected in sOGP10-14 treated mice. On day +10 the WBC increase in sOGP10-14-treated mice was comparable to that found in G-CSF treated ones. Moreover, CD34/Sca-1 positive early precursors were significantly mobilized by sOGP10-14 compared to the control group. In sOGP10-14-treated mice, the colony-forming unit-granulocyte-macrophage-megakaryocyte (GEMM-CFU) and burst-forming unit-erythroid (BFU-E) were significantly increased in bone marrow cells in comparison to mice treated with CTX only. These results suggest a central role of sOGP10-14 in bone and bone marrow interaction, and a possible role of sOGP10-14 as a mobilizing agent.