How do digital start-ups innovate? This is one of the main questions that the present report seeks to shed some light into. Using Henry Chesbrough's pioneering work as a starting point, the author sets out to determine how five digital start-ups from the North-East of England manage their innovation processes, and if, eventually, they practice Open Innovation. The research method that was used in the present dissertation is a multiple case study, in which the managers of all five enterprises, which consist mainly of mobile application and software developers, were thoroughly interviewed....