Introduction: After the surgical removal of a cerebella-pontine angle tumor (mainly vestibular schwannoma), and despite the anatomical integrity of the facial nerve, an immediate or delayed facial palsy may occur. This palsy may be explained by ischemia, edema, inflammation, or a neurotmesis (ruptured axons in an intact nerve sheet). This phenomenon is highly dependent on the size of the tumor. In our preliminary studies, we observed an immediate facial palsy in 16% and a palsy occurring at postoperative day 8 in 23% of the patients operated on for a vestibular schwannoma. Corticosteroids may decrease the inflammation and the edema around the nerve and reduce the incidence of the postoperative facial palsy. Their efficiency has already been demonstrated in idiopathic facial palsy. In a previously published study , a single dose of dexamethasone during surgery did not influence the facial function outcome. But the short period of the treatment do not allow definitive conclusions.