Some imaging data show that the average growth of an acoustic neuroma is about 2 millimeters per year. However, there is variability in the rate of tumor growth. A subset of patients have tumors that do not grow for as early as a few years and then begin to grow. Other patients have tumors that remain unchanged for years. In yet another group of patients, the tumors grow very rapidly For older patients, the average survival rate for acoustic neuromas is now unclear. For older patients (age 70 or older) with smaller tumors (less than 3 cm in diameter) and mild symptoms, we advocate serial cranial imaging to observe tumor changes. Patients selected for observation should have serial tumor imaging exams, approximately every 6 months in the early stages and annually thereafter. With this method, even very small tumor growth can be detected, and if the tumor grows then a decision can be made for surgery or gamma knife treatment.