The purpose of this paper is to increase the understanding of how knowledge and uncertainty can affect relationship commitment between companies in the international market. Therefore, knowledge accumulation, the various levels of uncertainties and the creation of business relationships will be examined. In order to achieve the purpose of the study the main research problem is formulated: How do Knowledge and uncertainty levels related to relationship commitment of internationalized firms?This thesis is based on the qualitative method since the aim of this study is to understand and analyse a phenomenon not quantitatively to measure it. This research is further based on the deductive approach since we have formulated our main research question on the basis of previous theory and apply it on real life cases. The empirical data is collected through a multiple case study with three companies active on the international market.The study's conclusion indicates that relationship commitment has an impact on knowledge and uncertainty in the international context. We demonstrate this by proving that companies can through relationships accumulate the necessary knowledge needed to reduce uncertainty in international business. Thus reducing the gap between knowledge possessed by the firm and knowledge needed to perform an international activity.