THE BEST treatment of complications is prevention. To date in acoustic tumor surgery we have not yet learned how to completely prevent any of the complications associated with the treatment of these lesions. Fortunately, however, we have greatly decreased the incidence of complications, and it can therefore be said that we avoid them in most cases. The incidence of complications in small and medium tumors is quite low, and this speaks forcefully for early diagnosis and management. We shall discuss surgical complications in order of their appearance: those occurring during surgery, thrombosis and bleeding; those occurring in the immediate postoperative period, edema and hemorrhage; and late complications of cerebrospinal fluid (CSF) leakage. Thrombosis of the Anterior-Inferior Cerebellar Artery Atkinson,1 in 1949, published what we consider one of the most important articles in the literature on acoustic neuroma. This is an article on the anatomy of the anterior-inferior cerebellar artery