In order to keep up with increasing competition companies use acquisitions to change or grow. Acquisitions are changes, and they do have an impact on organizations and its employees. When an acquisition takes place, two previously independent organizations and organizational cultures comes into contact, which causes changes in those cultures. These changes and the adaptation of the cultures can be described by the context of acculturation. Previous research in acculturation mainly focuses on determinants or acculturation outcomes. This study will therefore study the acculturation process. The purpose of this thesis is to describe and understand what the acculturation process look like after an acquisition. The method chosen for this thesis is qualitative, and the information has been collected by using semi-structured interviews. The study is a multiple case study and three cases are studied. We conclude that the acculturation process of acquired company is affected by several factors. What does the acculturation process look like after an acquisition can be understood by looking at these different factors and by finding reasons for what these factors are. Most strikingly, this study found that the acculturation process could not be understood separately from the acquisition process. Furthermore, in theory proposed agreements are not made in practice. The outcomes of this research are presented in a new model of the process of acculturation.