Background: One-third of people with epilepsy have drug-resistant epilepsy, making surgical treatment necessary. Comprehensive pre-surgical evaluations, including long-term video-electroencephalographic (VEEG) monitoring, magnetic resonance imaging (MRI), and neuropsychological testing, are essential components of epilepsy presurgical evaluation. The Epilepsy Center at the Mongolian-Japanese Hospital of MNUMS was established in September 2022 and introduced long-term video-EEG monitoring in May 2023. This marked the first time in Mongolia that comprehensive evaluation for epilepsy surgery became available. Aim: To evaluate the role and outcomes of long-term video-EEG monitoring in the pre-surgical assessment of epilepsy patients Materials and Methods: A prospective cohort study was conducted at the Epilepsy Center of the Mongolian-Japanese Hospital from May 2023 to March 2025. Patients who underwent VEEG and comprehensive pre-surgical evaluation were included. Data included demographic information, seizure history, imaging findings, and neurophysiological assessments (routine, sleep-deprived, and long-term video EEG). Patients were divided into two groups based on whether they met criteria for epilepsy surgery, and surgical outcomes were compared between these groups. Results: A total of 297 patients (104 children and 193 adults) participated in the study. Of these, 96 (32%) were diagnosed with temporal lobe epilepsy and underwent pre-surgical evaluation. The mean age of this group was 33±9.2 years; male-to-female ratio was 1:1. Age of seizure onset was 20±10.9 years, and the mean duration of epilepsy was 14.8±10.3 years. Etiologies included meningitis (21.7%), febrile seizures (15.2%), birth complications (12.5%), and traumatic brain injury (12.5%). The average duration of VEEG monitoring was 1.45±0.68 days, during which 161 seizures were recorded (average 2.64 per patient). No seizures were captured in 35 patients. Among the 96 patients, 29 met the criteria for surgical intervention, and 11 underwent temporal lobe epilepsy surgery. Surgical outcomes were significantly better compared to the non-surgical group (p<0.05). Conclusion Long-term video-EEG monitoring plays a critical role in precisely localizing the epileptogenic zone, identifying seizure types, establishing differential diagnoses, and optimizing surgical candidacy. It is confirmed as an essential diagnostic tool in the pre-surgical evaluation for epilepsy surgery.