Banking industry is undergoing unprecedented changes driven by consolidation by means of mergers and acquisitions all over the world. To procure the benefit of economies of scale, merging and acquisition has become one of the principleobjectives of many banks. Merger of SBI with its 5 associate banks namely State Bank of Bikaner and Jaipur (SBBJ), State Bank of Mysore(SBM), State Bank of Travancore (SBT), State Bank of Hyderabad (SBH), State Bank of Patiala (SBP) and Bharatiya Mahila Bank took place on 1stApril, 2017 is the largest merger in history of Indian Banking Industry.The merger had made State Bank of India one of the 50 biggest banks of the world. The study would enumerate the reasons why State Bank of India (SBI) has been merged with its associate banks, its impact on its stake holders. It also discusses the benefits to the customers and its associated banks.