Demyelination is a common sign of peripheral nerve injuries (PNIs) caused by damage to the myelin sheath surrounding axons in the sciatic nerve. There are not many methods to induce demyelination in the peripheral nervous system (PNS) using animal models. This study describes a surgical approach using a single partial sciatic nerve suture to induce demyelination in young male Sprague Dawley (SD) rats. After the post-sciatic nerve injury (p-SNI) to the sciatic nerve, histology and immunostaining show demyelination or myelin loss in early to severe phases with no self-recovery. The rotarod test confirms the loss of motor function in nerve-damaged rats. Transmission electron microscopic (TEM) imaging of nerve-damaged rats reveals axonal atrophy and inter-axonal gaps. Further, administration of Teriflunomide (TF) to p-SNI rats resulted in the restoration of motor function, repair of axonal atrophies with inter-axonal spaces, and myelin secretion or remyelination. Taken together, our findings demonstrate a surgical procedure that can induce demyelination in the rat sciatic nerve, which is then remyelinated after TF treatment.