The authors report the case of a 37-year-old woman in whom the trochlear nerve was transected during removal of a meningioma in the cavernous sinus and subsequently repaired by using microsurgical techniques. This patient presented with a tumor in the posterior part of the right cavernous sinus with expansion over the tentorium. Preoperatively, she suffered from partial deficit of the right trochlear nerve. Intraoperatively, the trochlear nerve was noted to be completely encased by the tumor and was totally divided during removal of the lesion. After tumor resection, the trochlear nerve was repaired by using a sural nerve fascicle secured with sutures and fibrin glue. Six months after the operation, trochlear nerve regeneration became evident as the patient's binocular vision gradually improved. The patient regained normal functioning of the superior oblique muscle 3.5 years after surgery. It is concluded that repair of a divided trochlear nerve is worthwhile and can be followed by successful regeneration and an excellent functional recovery of the superior oblique muscle.