The goals of the pituitary tumor surgery are restoration of the normal pituitary function and relieving the mass effect on the adjacent normal brain structures. The main purpose of this study is to analyze our surgical results of growth hormone(GH) secreting pituitary adenomas which were treated extensive and aggressive surgical removal. The surgical results were reviewed in 36 patients treated between 1993 and 1997. The criteria of clinical remission are postoperative basal GH less than 5ng/ml and suppression of GH less than 2ng/ml in oral glucose tolerance test. As the results, 25 of 36 patients(69.4%) achieved surgical remission. Eleven patients who could not achieve remission by surgery were treated with medical treatment(octreotide, bromocriptine) and Gamma-knife surgery. In conclusion, the tumor morphology and extensiveness of tumor removal were well correlated with surgical outcome, and the aggressive resection of tumor seems to be the most important factor achieving remission in GH secreting pituitary adenomas.