The objective of this study is to provide a literature review consisting of studies investigating the impact of mergers and acquisition (M&A) transactions at the micro and macro levels. The review has three different parts. In the first part, the focus is on the macro effects of M&A transactions and the impact of these transactions at the industry and market levels as well as their determinants are investigated. The second part comprises studies analyzing the effects of M&A transactions on the financial performance of the acquirer and target companies. In the third and final section, the factors affecting the financial performance changes as a result of M&A transactions are discussed.