Integration processes represent the core of the company's external growth strategy. Merger and acquisition transactions stand out as the main integration techniques, while strategic alliances and joint ventures are alternative methods of connecting companies. For the Croatian banking sector, as well as for the economy as a whole, the acquisition of Splitska banka by OTP banka is one of the most significant events in recent history. The purpose of the thesis is to investigate how the integration of Splitska and OTP banka affected the operations of OTP banka, their clients and employees, as well as the clients and employees of the former Splitska banka. The operations of OTP banka before and after the acquisition transaction and the operations of Splitska banka before the acquisition were analyzed through financial indicators. The analysis showed that the profitability and economic efficiency of OTP banka's operations were higher in the period after integration compared to the period before integration. Liquidity and indebtedness indicators in both observed periods remained at the same levels. The relevant conclusions about OTP banka's client satisfaction and employee opinions were made on the basis of empirical research. The majority of respondents who are OTP banka's long-term clients state that they did not feel the consequences of the acquisition of Splitska banka and have been equally satisfied with the work of OTP banka in general. On the other hand, for most of Splitska banka's former clients, the consequences of acquisition were more pronounced - both positive and negative. The majority of employees of OTP banka and former Splitska banka agree that the integration period was more challenging compared to other periods of working in the bank. Also, employees state that there were changes that affected them directly after the integration.