Mergers and acquisitions has become a common thing in recent years. Assets change owners in hope of creating synergies and desirable outcomes. Human capital, i.e. the employees behind the numbers, is one asset that is often forgotten. It is therefore important to keep these key employees in the organisation post-acquisition in order to gain or retain competitive advantages and avoid unwelcome surprises. The aim of the study is to identify how Swedish medtech companies identifies key employees during a due diligence and how they retain them afterwards. We chose a qualitative approach for the study and have therefore conducted our interviews in a semi-structured manner. The study uses competence- and resource based theory to identify key employees and how to use them as a resource to gain a competitive advantage. Our result is that human capital is not a factor that can sustain a competitive advantage since it can be transferred via mergers and acquisitions. On the other hand, the competence based view can be used to maximize the resources in form of human capital. When a company is acquired, employees start integrating in the new organisation. The study uses onboarding theory to identify key aspects in how to acclimatise key employees. A conceptual model is eventually presented with our findings where key employees are identified by way of references, the former board of directors, statistics, meetings and industrial knowledge. The HR-department does generally gets involved late in the due diligence process, something that our respondents consider a potential problem. In post-acquisition, during the onboarding process, key factors are; obtaining information about the new culture, role clarification and new challenges to keep key employees in the new organisation. Keywords: Human Capital, mergers & acquisitions, medtech, onboarding, key employee retention.