Businesses worldwide are confronting a more internationalized market. With this trend, companies frequently turn to international branding and rebranding initiatives through the acquisition of companies to grow. During this process, businesses are updating their brand identity and/or strategy, while also dealing with various challenges. Studies focusing on these challenges on the B2B field remain little explored and are necessary, due to its highly competitive characteristic. Especially in the life science industry, due to its institutional differences between national markets in the sector. Therefore, the overall research purpose in this licentiate thesis is to describe and understand how the international branding and rebranding process is developed in the life science industry. In this thesis, two studies were made to achieve this purpose. One literature review to explore the current literature of the field and one empirical study using a single case study method. The main contribution of this licentiate thesis is to describe in-depth how the brand rebranding process is implemented in the life science industry, and its main hinders. They are: internal and external legitimation. More importantly, this study presents a framework that demonstrates how businesses in emerging regions face more external legitimation challenges as a result of institutional constraints, as opposed to developed countries, where internal legitimation barriers are more prominent during the rebranding process. This licentiate thesis contributes to creating knowledge in international branding since it provides an overview of the past years of research in the area and suggests research gaps that need further investigation. In parallel, it generates insights into the analyzed process of international branding and rebranding, bringing understanding into the corporate brand area and the management of B2B brands in life science industries.