Current microsurgical treatment of vestibular schwannomas usually brings satisfactory results for the patients. However, transient or permanent complications may occur, especially when treating large tumors. Precise information about these potential complications has to be given to the patient at the time of the surgical decision. Based on their personal experience of large operated vestibular schwannomas and analyzing a review of the international literature, the authors detail these complications and the way to prevent and manage them. The problems that are linked to the variety of surgical approaches are also commented. The most frequent complication is cerebrospinal fluid leak that requires medical management and in less than one third of cases, surgical exploration. Vascular problems including ischemia or hemorrhage inside the posterior fossa represent the main source of permanent morbidity. Lower cranial nerve deficits are unusual but may expose to early and delayed aspiration pneumonias. The authors conclude that careful selection of cases, meticulous operative management and intensive postoperative care are essential steps to prevent and to treat these complications.