Actuality of the paper. The number of acquisition and merger transactions worldwide is growing. These transactions expand the potential of companies. Business managers are looking for internal and external investment opportunities. Internal investment refers to reorganizations and investments in the company itself; external investments are associated with the acquisition of new assets and projects. Companies need to consider another range of opportunities that involve interaction with other "market actors" and continuously look for such opportunities, comparing the potential of domestic growth and acquisitions and mergers. The consequences of globalization force companies to expand capital for more efficient use. But, despite the fact that mergers and acquisitions are attractive transactions, the issue of their efficiency is quite acute. The aim of the paper is to evaluate the efficiency of merger and acquisition transactions of companies, to analyze the financial results of business acquisitions and the success of their integration, which are influenced by many factors. Some of the factors are attributed to the management of the takeover transaction when it is at the stage of completion or the beginning of the company's integration processes and refers to the entire structure of the undertaking that is conducting the transaction. The other part of the factors has a greater impact on the projects that will be implemented during takeover, taking into account the risks. Research methods: analysis and synthesis, induction and deduction, intensive and observational method.