Objective Transsphenoidal surgery (TSS) is the first-line treatment for patients with Cushing's disease (CD). However, the reported remission rates of patients who received TSS vary widely between different studies, and the predictors of surgical outcomes remain controversial. The present study analyzed the early outcome of TSS in a large population of patients with CD at a single center, and identified potential predictors of initial remission of TSS in patients with CD. Methods The clinical features and surgical outcomes of CD patients who underwent TSS between 1988 and 2018 at Peking Union Medical College Hospital (PUMCH) were collected and analyzed from their medical records. Results Of the 1604 CD patients who underwent TSS at PUMCH between February 1988 and October 2018, 1106 patients had complete medical data and pathological results. After surgery, the overall postoperative initial remission rate was 72.5, and 27.5% of patients maintained persistent hypercortisolism. The initial remission rate of patients with preoperative noninvasive adenoma based on MRI (77.1%), intraoperative noninvasiveness (72.5%), microadenoma (74.3%), pathological confirmation (76.4%), and first TSS (73.9%) was significantly higher than that in patients with preoperative invasive adenoma (53.0%), intraoperative invasiveness (60.7%), macroadenomas (65.9%), pathologically negative (49.7%), and repeat TSS (56.0%), respectively (all P < 0.05). The initial remission rate in patients with pseudocapsule-based extracapsular resection (88.1%), MRI-visible adenoma (74.2%) was higher than that in patients without pseudocapsule-based extracapsular resection (77.1%), and with MRI-negative results (64.5%), respectively, but did not reach statistical significance (All P > 0.05). Striking, there was no significant differences in initial remission rates between patients who underwent selective adenomectomy and enlarged adenomectomy (P > 0.05). Whereas, the initial remission rates in patients who underwent partial hypophysectomy only was 51.0%, which was much lower than that in patients underwent selective adenomectomy and enlarged adenomectomy (P < 0.05). Conclusion The TSS is a safe and effective procedure for the treatment of CD. Whereas, preoperative invasiveness based on MRI, intraoperative invasiveness, macroadenomas pathologically negative, and repeat TSS are related to lower initial remission rates.