Between 1984 and 1989, 22 patients with pituitary adenomas were treated with radiation therapy. The tumor was controlled in 18 of 22 (81.8%) patients for an observed period of II to 98 months. Eleven of 12 (92%) patients with visual field defect experienced nomalization or improvement, and 3 of 5 evaluable patients with hyperprolactinemia achieved normalization in one and decrement in two patients. We concluded that: (a) postoperative radiotherapy is clearly effective in the controlling of clinical symptoms and signs resulting from pituitary adenoma: (b) In the macroadenoma, the difference of control rate between suprasellar, <2cm. And suprasellar,>2cm. Was not significant.