The main aim of this study is to address the integration problems and solutions that arise in information systems in business combinations or acquisitions. In this respect, the theoretical framework for the concepts is presented in detail, followed by an analysis of a data collection questionnaire for the relevant employees and managers of the businesses in different sectors for the purpose of the study. Finally, the research findings were summarized and interpreted, and a number of suggestions were made for future studies and practice. In the results of the analysis, it has been seen that problems in software, hardware, network and application layers appeared in the integration of information systems during mergers and acquisitions. Besides, solutions of the problems in these layers have been determined and presented.