This article presents findings of a retrospective evaluation of 489 patients who underwent vestibular schwannoma surgery and developed delayed facial palsy. The authors define delayed facial palsy as deterioration of at least two HB grades between postoperative days five and 30. There were 368 patients with House- Brackmann (HB) grade I to III facial palsy which developed between postoperative day five and 30 included in the study. Most patients were observed to recover function within one month of onset. Patients with HB Grade III palsy on postoperative day five who later developed delayed facial palsy required longer recovery periods, often more than 60 days. The authors did not find evidence of steroid or steroids plus antiviral medication influencing recovery in those who received these medications compared to patients who did not. Patients undergoing gross total resections or a retrosigmoid approach were found to be at a higher risk of developing delayed facial palsy. The study suggests that additional nerve manipulation required in gross total resections and introduction of bone dust into the subarachnoid space during internal auditory canal drilling via the retrosigmoid approach may lead to an inflammatory response leading to delayed facial palsy.