Objective: Analysis of preoperative predictors for pituitary adenoma operations and their impact on results after endoscopic endonasal transsphenoidal surgery (EETSS) Methods: We carried out a prospective study of all the patients (99), who were endoscopically endonated transphenoidal at the Department of Neurosurgery, Benha University, Egypt and Wuhan Union Hospital, and China between January 2018 and December 2019. Medical data were gathered and evaluated, including information on sex, age, tumour size, hormone level, preoperative MRI brain and sella, resection scope, result (clinical and endocrinological) and complications. Results: 99 patients with PA were endoscopic transsphenoidal endonasal treatments, 52 males (52.5%) and 47 females (47.5 percent ). Average age 42.5 ± 11.2 years, Irregular menstrual behaviour was the highest in the study populations in 22 patients, followed by visual disturbance in 17 patients (17.2%), acromegaly and increased intracranial pressure in 14 patients, followed by 11 (11.1%), 8 (8.1%) accidents, and 5 (8.1%) cases (11.1%), followed by headache with 11 (12.1%). Conclusion: the size and scope of the tumour excision are only important postoperative determinants (hormonal, radiological & postoperative complications).