Postoperative radiotherapy often is recommended in the treatment of clinically nonfunctioning pituitary adenomas to decrease recurrence rates. Radiotherapy, however, can be associated with a number of significant complications, including hypopituitarism, second malignancies, cerebrovascular accidents, optic nerve damage, radiation necrosis, neurologic dysfunction, and soft tissue reactions, which may outweigh the potential benefits in some patients. The decision to use radiation must include a careful assessment of the patient's general medical problems and life expectancy as well as the extent of tumor and outcome of surgery to determine the expected benefit of radiotherapy. Review of the literature on this subject reveals that detailed information about the factors that very likely influence recurrence rates, including tumor histology, size, degree of invasiveness, and completeness of resection, often is lacking, making proper interpretation of the data difficult. There does appear to be a subgroup of patients, however, with nonaggressive tumors who may have good outcomes with transsphenoidal surgery alone. Therefore, it seems reasonable to defer radiotherapy in patients without postoperative residual tumor or symptoms to avoid potentially serious consequences in a group that is probably at low risk for recurrence. However, careful follow-up of nonirradiated patients with periodic magnetic resonance imaging is necessary to detect tumor recurrence and the need for irradiation or repeat surgery