Activated platelets release various growth factors, some of which are recognized to improve nerve regeneration. This study evaluated the effect of platelet-rich plasma (PRP) in end-to-end neurorrhaphy. A total of 45 Wistar rats were used, with the initial five used for PRP preparation. The right hind limbs were used as experimental, with the left as control. The animals were treated in five groups. Group A (n = 4): The right sciatic nerve was dissected only from the sciatic notch to the bifurcation. In all other groups, the nerve was sharply transected and repaired with: group B (n = 8): two sutures; group C (n = 8): six sutures; group D (n = 10): two sutures and PRP; and group E (n = 10): six sutures and PRP. Groups D and E were compared with groups B and C, respectively. Group E had a shorter latency time in electromyography (p < 0.01) and a thicker myelin layer in the histological evaluation (p < 0.003) in comparison with group C. These positive effects of PRP were not detected in the nerves were repaired with two sutures. In this animal model, the application of PRP to the repair site helped to improve remyelinization of the sciatic nerve in rats when the epineural repair was done with six sutures.