This study examines the effect of mergers and acquisitions in the Nepalese banking industry on employee performance, focusing on the influence of work culture, training and performance appraisal, pay and allowances, and transfers and promotions. A descriptive and casual-comparative research design was used, with data collected through a self-administered survey questionnaire. Convenience sampling was used to select 31 branches of commercial banks, resulting in 212 responses. Descriptive and inferential statistics were used to analyze the data, including correlation and regression analysis. The results indicate that work culture, training and performance appraisal, transfers and promotions, and pay and allowances affect employee performance after a merger or acquisition. For a successful merger or acquisition, banks must effectively communicate with employees and provide adequate training to help them adjust to cultural and structural changes.