The generation of various pluripotent stem cell lines provides a new route to investigate developmental process of germ cell and embryo development, which until now was difficult to access in the human. In the future these cells may be used for new therapies in reproductive medicine. This brief review outlines the development of germ cells and their pluripotent capabilities, how embryonic and germline stem cells can mimic developmental processes in vitro and generate gamete and trophoblast phenotypes for research and potential treatments.