BACKGROUND: We sought to determine the effect of positive neural margins on subsequent facial nerve function following facial nerve grafting. METHODS: In this retrospective review, 19 patients had sacrifice of their facial nerve with immediate facial nerve grafting, 8 had positive neural margins, and 11 had negative neural margins. Facial nerve function was analyzed using the House-Brackman scale. RESULTS: In the first group (8 patients), 5 had positive proximal margins and 3 had positive distal neural margins. Outcome by House-Brackman score was III (2 patients), IV (3 patients), V (1 patient), and VI (2 patients). In the second group (no evidence of neural spread, 11 patients), outcome was III (3 patients), IV (2 patients), V (2 patients), and VI (4 patients). CONCLUSION: No significant difference in the outcome of facial nerve function was seen between these 2 groups. Facial nerve grafting should be considered in patients whose facial nerve is sacrificed, even when there is evidence of tumor in the perineurium at the margin of resection.