Objective: This study is designed to evaluate the clinical outcome, the safety and the effectiveness of the open sella methods(OSM) with intentionally staged transsphenoidal approach(TSA) for giant pituitary adenomas(GPA). Methods: Eight patients with GPA were managed by the OSM with intentionally staged TSA. There were 5 nonfunctioning adenomas, 2 prolactin-secreting adenomas, and 1 growth hormone-secreting adenoma. Among them, 6 patients underwent two times of TSA, one patient underwent three times of TSA, and the other patient underwent two times of TSA followed by radiation therapy. The mean time interval between staged operations was 3.9 months except for one case. Results: Seven out of the eight patients with GPA treated with the OSM with intentionally staged TSA showed that the tumors were completely removed on magnetic resonance imaging and that they were free from headache and visual problem suffered previously. Only one patient experienced severe complications including panhypo-pituitarism, cerebrospinal fluid rhinorrhea and permanent diabetes insipidus. Conclusion: With the surgical treatment for 8 cases of GPA, which extended to the suprasellar and parasellar area, we suggest that the OSM with intentionally staged TSA is a safe and effective method in management for GPA.