Three cases of fat graft prolapse into the cerebellopontine angle with clinical deterioration are presented. These patients had undergone translabyrinthine craniotomy for cerebellopontine angle tumors and had autologous abdominal fat strips placed to obliterate the dural defect and the mastoid cavity. Two patients suffered significant morbidity, and one patient died. Clinical presentation, computed tomographic scan findings, methods of treatment, and avoidance of this complication are discussed.