Due to the moderately small market of Sweden, firms expand and conducts business on an international level in order to find new opportunities and increase the profits. Many Swedish multinationals expand to the Russian market, due to its size regarding customer base and landmass. Thus, the aim of this study is to provide a greater understanding of how informal institutions in Russia are influencing Swedish multinationals’ establishment and development in the Russian market. Appropriate aspects of informal institutions have been acknowledged and identified with a further analysis in relation to internationalization, culture, and network. A qualitative research method was implemented in this study with the aim to obtain a greater understanding of informal institutions and the way it affects the Swedish firms in Russia. Furthermore, this study used abduction as a research approach, since the authors of this thesis switched between theory and empirical data to make adjustments during the process that enabled the authors to be flexible while gathering the data. The literature review that is presented in this study has a link to internationalization, culture, network and lastly informal institutions. Through combining the presented literature review, the authors developed a conceptual framework that further was used when analyzing the empirical data, collected from multi-case studies of Swedish multinationals. The analysis section discusses both similarities and dissimilarities between the theory and the empirical findings. These analyses are designed in relation to the conceptual framework. The final chapter of this thesis will contain conclusions that were derived from the material in the analysis chapter. Furthermore, the theoretical implications and a revised theoretical model will be presented. Additionally, the managerial implications will be presented along with limitations of the study and the study will be concluded with suggestions for further research. The main theoretical implications that have been developed during this thesis, contains reducing the research gap and continuing with a demonstration of how Russian informal institutions influence Swedish multinational’s establishment and development in the Russian market. The main practical implication of this study is to aid the business procedures of Swedish companies in the Russian market. Moreover, this study can be of practical use to Swedish firms that are in the process of or planning to internationalize to the Russian market.