Business angels play an important role in financing small and medium-sized enterprises as well as generously contribute to their future development, growth and overall success. A particular and nowadays widely known disparity distinguishing business angels from other potential investors is that besides the financial support, they offer their expertise, know-how and an exclusive access to relevant networks. But how these additional resources are exercised and what actually happens after the financial investment is made? What is the level of the involvement business angel undertakes in the start-up and does it fluctuates? Aim of this research is to contribute to the existing literature in the field of business angels with an evidence from a research conducted in Denmark. Research investigates a cooperation between a business angel the CEO of the start-up.