Video endoscopy systems give physicians the ability to inspect internal structures of the human body by using a camera with attached endoscope optics. This technology has become a routine in clinics all over the world. Moreover, video endoscopy systems recently performed a technological change from PAL/NTSC image resolution to HDTV. There is a vast of literature on in-vivo and in-vitro experiments with multi-spectral point and imaging instruments that document that the spectral information can be a valuable diagnostic decision support. Due to the fact that spectral imaging equipment was too slow to acquire hyper-spectral image stacks at reasonable video rates, intra-surgery hyper-spectral measurements were limited to point measurements in the past. But the availability of fast and versatile acousto optical tunable filters with switching times in the microsecond range made the application of a hyper-spectral video endoscope technically feasible. This paper describes a demonstrator of a hyper-spectral video endoscope, the data analysis and the results of the first clinical studies. The results show that hyper-spectral video endoscopy exhibits a large potential to become an important imaging technology for medical imaging devices that provide additional diagnostic information about the tissue under investigation.