The aim of this study was to identify the effect of erythropoietin (EPO) on a sciatic nerve injury model. The effect of single or repeated doses was also determined. Twenty-one Wistar rats were anesthetised and the sciatic nerve was transected 1 cm above the trifurcation and the nerve was repaired with four epineural 10/0 nylon sutures placed at 90 degrees intervals under microscope magnification. The rats were divided into 4 groups as follows: the sham, the saline, the single dose EPO and the multiple dose EPO. The skin was incised and closed and no treatment was given in sham group. In the saline group, 1 mL saline was given intraperitoneally; in the single EPO group, 5000 U/kg EPO was given intraperitoneally immediately after the procedure. In the multiple EPO group, 5000 U/kg EPO was given after the procedure and the same dose was repeated after the 1st, 2nd, 3rd and 4th weeks. Functional recovery was evaluated by static sciatic functional index(SSI). Single EPO group had greater myofibril size, axon number, diameter, and ratio M than the saline group. The multiple EPO treatment was not found to be more effective than single EPO treatment. However, no significant difference was found between the single EPO, multiple EPO, and saline groups based on the 3rd and 4th postoperative month SSI scores. Thus, EPO treatment increased axonal regeneration in our study. However, repeated dose therapy was not found to be more effective than single dose therapy. The optimum dose and duration should be researched in further studies.