Between November 1994 and June 2001, 194 patients with Cushing's disease underwent transsphenoidal surgery: 167 patients had adenomectomy, 14 had ante hypophysectomy, 5 had subtotal hypophysectomy, 4 had hemihypophysectomy 4 had central hypophysectomy. Complications occurred in 18 patients (9.3%), including 4 deaths (three were apparently not related to surgery). Remission of disease was achieved in 162 of 190 (85.3%) patients analyzed. Surgical failures were associated with lack of pituitary adenoma, size of the tumor and invasiveness. Among patients with confirmed adenomas, the rate of remission was significantly higher (p<0.01) in patients with microadenomas (92.6%) than in patients with macroadenomas (66.7%). Reoperation in 6 failures was followed by remission in 4 cases. The overall remission rate was 87.4%. In the 162 patients with immediate success, duration of follow-up was 10.0 +/- 5.9 years (m +/- DS; median=10.0). Recurrence of the disease occurred in 24 (14.8%) of 162 patients at a mean 4.8 years (range: 0.8-12.0 years). Our longest sustained remission is 25.6 years. Actuarial analysis indicates that the probability of a patient remaining well 12 years after surgery is 80.0%. It is 86.2% in microadenomas versus 52.5% in macroadenomas and 94.5% in the patients with postoperative hypocortisolism versus 59.2% in the others.