Companies use merger and acquisitions, M&A, as a strategic choice to boost the firm. But even though M&As are a common way to boost the company, the failure rate is 70-90%, indicating the need to explore success factors. The objective of this study is therefore to establish a deeper understanding about how a Swedish firm conducts an acquisition, to give insights about essential elements during the acquisition process. This is achieved by answering the research questions: what are the success factors influencing the performance of an acquisition in Sweden, as well as how is the acquisition process successfully managed in a Swedish firm. By investigating these questions, the study will give insights about essential elements during the acquisition process, with the aim to increase the success rate. By analysing the management team within one single company, we were able to investigate a single case deeply and acquire their opinions and ideas. Due to the fact the managers are the ones steering and controlling the firm, it was necessary for us to comprehend their opinions. The study has taken a qualitative research approach, and six semi-structured interviews were held with the management team of our analysed firm. The empirical material has been analysed and compared with previous research within the subject. The theoretical framework discusse dM&As by covering the subjects, management, organisational change, culture, and success factors. Based on the empirical findings along with previous scientific articles, the research questions have been analysed and answered in the conclusion. Conclusively, we found eleven different success factors influencing the performance of an acquisition in Sweden, whereas seven of them have been found earlier in various studies and the additional four comes from our empirical findings. The additional four success factors are to be flexible, to be present, stand on common ground, and establish fellowship with the employees. The conclusion of adding these four comes from the greatest obstacle an organisation can face during an acquisition, getting the staff on board. Our second research question was about how the acquisition process is successfully managed in a Swedish firm. Where the conclusion is that the analysed firm endeavours to be honest and open with the employees, as well as being present and on site. Furthermore, the senior managers surround themselves with people they believe in. This to achieve the capacity to acquire another company. When looking at a potential firm the analysed firm believes it can be beneficial to have a sceptical mindset, to minimise the risk of making wrong estimation of the synergies. When the firm has acquired another firm, the senior managers strive to be flexible, and have the ability to adjust their leadership style depending on the situation.