Mergers and Acquisitions are taking place and have dramatically increased in every industry, and the banking industry is not left untouched. As we all know, the banking sector plays an important role in the Indian economy, and it is like a base of the Indian economy. In the last five years, most of the public sector banks were merged for the betterment of the banking industry, and 12 nationalized public sector banks remain after merger and acquisitions. Everything has its own advantages and disadvantages. So Mergers and Acquisitions also have their own advantages, such as - minimized operating expenses, a rise in the share, it prevents the shutdown of an unsuccessful business, avoiding duplication, etc., and disadvantages like:- a breakdown in communication, it creates joblessness, no working experience in the past, strict evaluation, complicated situations, etc. Apart from these things, many bank employees have experienced many psychological effects of mergers and acquisitions. The purpose of this research was to study the effects of the merger and acquisition process on the job satisfaction level of bank employees. For this purpose, the Job Satisfaction Scale (Developed by B. L. Dubey) was used to collect data from 100 bank employees from various banks in the Patna District of Bihar aged between 25 to 50 years. Analysis was done with the help of statistical techniques like mean, SD, and t – value. The result of this study reveals significant differences in job satisfaction levels among Erstwhile and Acquisition Bank Employees as well as officers and clerks groups belonging to the same bank.