Purpose: This study was done to analyze survivals, local control, improvement of symptoms, and complications of nonfunctioning pituitary adenoma after radiation therapy. Materials and Methods : Radiation treatment results were analyzed in a retrospective analysis of 103 patients with nonfunctioning pituitary adenoma treated with radiation or combined with surgery from 1979 through 1990 at the Department of Therapeutic Radiology of Seoul National University Hospital. Radiation doses of 4000-5540 cGy were delivered over a periods of 4~7 weeks. Results: The 10-year overall and progression-free survival rates for all patients were 88. 6% and 85.2%. The tumor was controlled in 91 of 103(90.4%) patients for an observed period of 17 to 165 months. Sixty-two of 88(70.5%) patients with impaired visual acuity and 54 of 85(64.3%) patients with visual field defect experienced normalization or improvement. The only prognostic variable identified by univariate analysis to significantly alter progression-free survival was the extent of visual field defect(p=0.04). Conclusion: We concluded that radiotherapy is clearly effective in tumor control and controlling of clinical symptoms and signs resulted from nonfunctioning pituitary adenoma.