Objectives: To study the functional, histopathological and immunohistochemical effect of cyclosporine A on sciatic nerve regeneration using allografts in a rat sciatic nerve model.Methods: Thirty male white Wistar rats were divided into three experimental groups (n = 10), randomly: Normal control group (NC), allograft group (ALLO), CsA treated group (ALLO/ CsA). In NC group left sciatic nerve was exposed through a gluteal muscle incision and after homeostasis muscle was sutured. In the ALLO group the left sciatic nerve was exposed through a gluteal muscle incision and transected proximal to the tibio-peroneal bifurcation where a 10 mm segment was excised. The same procedure was performed in the ALLO/ CsA group and the animals were treated with interaperitoneal administration of cyclosporine A. The harvested nerves of the rats of ALLO group were served as allograft for ALLO/ CsA group and vice versa. The NC and ALLO groups received 300 μL sterile olive oil interaperitoneally once a day for one week and the ALLO/ CsA group received 300 μL CsA (1mg/kg/day) interaperitoneally once a day for one week.Results: Behavioral, functional, biomechanical and gastrocnemius muscle mass showed earlier regeneration of axons in ALLO/ CsA than in ALLO group (p=0.001). Histomorphometic and immunohistochemical studies also showed earlier regeneration of axons in ALLO/ CsA than in ALLO group (p=0.034).Conclusion: Administration of CsA could accelerate functional recovery after nerve allografting in sciatic nerve. It may have clinical implications for the surgical management of patients after nerve transection in emergency conditions.