As globalization processes, an increasing number of companies use mergers and acquisitions as a tool to achieve company growth in the international business world. The purpose of this thesis is to investigate the process of an international M&A and analyze the factors leading to success. The research started with reviewing different academic theory. The important aspects in both pre-M&A phase and post-M&A phase have been studied in depth. Because of the complexity in international M&A, a qualitative method has been used in the research. The empirical findings of the case study have mainly been collected from.semi-structured interviews. The investigation shows that an international M&A is a tried-and-tested process from initial identification to integration. The process can be summarized into five steps: identification, evaluation, negotiation, implementation and integration. The important factors contributing to the success of international M&As are found to be corporate selection capability, cultural differences, human resources and communication.