A 23-year-old male patient developed aplastic anemia and was treated with cyclosporin A and rhG-CSF. Bone marrow biopsy showed an improvement in cellularity with a recovery of all hematopoietic precursors after nine weeks of therapy. WBC increased after two weeks of treatment, mostly due to an increase in the absolute granulocyte cell count. Hb, RBC, Plts and reticulocytes showed an increase six weeks after the beginning of therapy. Of the serum cytokines, EPO levels progressively decreased, while sTfR increased in peripheral blood. A reverse correlation between blood neutrophil count and serum levels of G-CSF was observed, indicating an increased clearance of G-CSF. Finally, sIL-2R showed a rapid increase in the first week of treatment and prior to the increase in PMN cells. Thus, the use of cyclosporin A and rhG-CSF in our patient induced a complete recovery of hemopoiesis, and this may be explained by a synergic effect induced by the capacity of cyclosporin A to remove inhibitory factors and the stimulatory activity of rhG-CSF.