Background: During laparoscopic surgery, pneumoperitoneum and Trendelenburg positioning applied to provide better surgical vision can cause many physiological changes as well as an increase in intracranial pressure. However, it has been reported that cerebral autoregulation prevents cerebral edema by regulating this pressure increase. Study aimed to investigate whether the Trendelenburg position duration had an effect on the increase in ICP using the ultrasonographic measurement of ONSD. Materials and Method: This prospective observational study included 60 female patients aged 18-65 years, with American Society of Anesthesiology (ASA) status I and II, undergoing laparoscopic hysterectomy. Optic Nerve Sheath Diameter (ONSD) measurement was measured using ultrasound imaging in both sagittal and transverse planes of both eyes. Prior to anesthesia induction, baseline measurements were obtained in the neutral position without applying high pressure. The first measurement was taken before anesthesia induction and the second measurement was taken 2 minutes after endotracheal intubation, in the neutral position.Once the patient was positioned in the Lloyd Davies position after trocar placement and the establishment of pneumoperitoneum, subsequent ONSD measurements was taken at 30 minutes, 60 minutes, 75 minutes, and 90 minutes of surgery. At the end of the procedure, once pneumoperitoneum and the Trendelenburg position were neutralized, a final measurement was taken 5 minutes after the patient was returned to the neutral position. All measurements were conducted by the same anesthesiologist to minimize inter-observer variability. Results:The majority of patients were aged 41-60 years (50%), followed by the 20-40 years age group (41.7%). Most patients (58.3%) were classified as ASA I, indicating they were generally healthy, while 41.7% were classified as ASA II, meaning they had mild systemic disease. The majority of patients had anormal weight (66.7%), with 20% being classified as overweight (25.0 - 29.9 kg∕m2). Most patients (58.3%) stayed in hospital for 2-3 days after surgery. 20% of patients were discharged on the same day, and 21.7% stayed for more than 3 days. The majority of surgeries lasted between 120-150 minutes (50%), followed by those lasting more than 150 minutes (36.7%). The mean ONSD measurements at each time point showed that there was a gradual increase in ONSD as the duration of the surgery and Trendelenburg position increased. Trendelenburg position duration contributed to an increase in ICP. Conclusion: Prolonged Trendelenburg positioning during laparoscopic hysterectomy leads to a gradual increase in ONSD, which may reflect a transient increase in ICP. These changes appear to be reversible following surgery, suggesting that the brain’s compensatory mechanisms are sufficient to maintain stable ICP during short laparoscopic procedures.