Developments, trends, business climate, conditions, factors influencing the efficiency and results of mergers and acquisitions (M&A) in the energy sector are explored in this research. PESTLE (political, economic, social, technological, legal, environmental) analysis was performed in order to determine the driving forces of M&As in the energy industry. Considering the motivation and main questions of the study, a sample of global M&A deals that have occurred during the period 1995−2020 has been analyzed. DataStream 5.1 database by Thomson Reuters was employed to identify the sample of global energy companies that took over another company in the period 1995−2020. According to the research, while the role and presence of M&As in the energy industry are increasing, the purpose of the M&A deals has changed remarkably. During 1995−2010, most M&A events were conducted in order to explore synergies and benefit from cost reduction. Since the last decade, firms are pursuing M&As in the search of growth opportunities, ensuring supply and reflecting demand for green development of ecological environment and ongoing changes in the nature of energy.