Image-based high content screening (HCS) is rapidly gaining recognition as the future of drug discovery. The ability to screen vast amounts of possible therapeutic agents in a relatively short time, while obtaining various levels of information about each target cell's biology, has an immense potential. Moreover, since the screening is done using cells, it is possible to look for a broader phenotype than, for example, when focusing on the activity of an isolated enzyme. This allows the search for new drugs for diseases with unknown molecular hallmarks or with multifactorial causes. The recently achieved advances in human stem cell research have opened the way to a new horizon in medical technology. Our ability to manipulate these cells will allow us to change the focus of drug development from generic to personal. Consequently, it will be possible to characterize the efect of a repertoire of available therapies for a certain disease using the cells obtained from a certain individual. This would ofer an unparalleled achievement, and its contribution to the success rate of treatments could prove truly astronomical. Similarly to the way high-content screening is revolutionizing the process of drug discovery, the application of these methods using human stem cells together with nanotechnology for improving targeted drug delivery, is expected to produce the next major breakthrough for personalized medicine in the pharmaceutical industry.