Intrinsic focal tumor of the medulla oblongata is an uncommon entity. Of the 51 cases presenting for treatment of a brainstem glioma between 1984 and 1990, only 7 were confined to the medulla. Radical excision was performed on each patient. Four of the first 5 patients who were extubated in the recovery room had CO2 retention, with associated respiratory arrest and hypoxia. Three suffered permanent cranial nerve deficits as a result. It is the purpose of this report to describe the serious complications of medullary surgery and to make recommendations as to how they may be avoided.