This thesis aims to explore what and how Swedish micro firms use digital media towards relationship initiation in a Business-to-Business (B2B) context. Digital media has been increasingly studied in marketing over time, but it has been predominated by Business-to- Customer (B2C) context, while the Business-to-Business context lacks attention, micro B2B firms even less in particular. Moreover, previous studies show that micro B2B firms lack knowledge of how to leverage digital media and thus they have not fully exploited the benefits in relationship marketing. Therefore, this thesis anticipates gaining a better understanding of the phenomenon of digital media use by micro B2B firms towards customer relationships and focuses on the initiation stage due to its importance in the relationship marketing process as well as the limited knowledge in existing literature.  This thesis employs a qualitative and multi-case study approach to explore the focal phenomenon. Four micro companies which have less than 10 employees from the life science industryparticipate in the empirical study. The data comes from semi-structured interviews and observation of their websites and social media accounts. Each firm has conducted two interviews. The data analysis follows the Gioia methodology, including within case and across cases analysis, as well as the theory elaboration study.  This study shows that Swedish micro B2B firms rely on their own websites, email, and social media mainly LinkedIn to communicate with potential customers, hence fostering relationship initiation. These digital media have been used to trigger the interest of potential customers, establish credibility by knowledge sharing, and create value. The findings contribute to the literature by extending the knowledge of what and how digital media is used by micro B2B firms towards relationship initiation. They are in line with extant literature showing that digital media enables companies to attract customers, engage their participation, and meet as well as provide services online. In addition, they confirm that digital media can enhance their trustworthiness due to increased communication and interaction. Furthermore, the findings identify the processive process of the case firms and their potential customers from unfamiliarity to relationship initiation, which illustrates three levels of interactivity in sequence: message-based level, knowledge-based level, and participant-based level. The progress of interactivity indicates the development of the trust of potential customers.  This thesis sheds light on what digital media micro B2B firms use and how to use towards relationship initiation with unfamiliar potential customers. Also, it provides insights into how micro B2B firms could establish and increase their trustworthiness in the market. Additionally, this thesis extends the managerial implications to the society and other stakeholders.