© Springer International Publishing Switzerland 2015. To get approval for initiating a stem cell clinical trial is becoming increasingly difficult because of the stringency of regulatory guidelines. The first section of this chapter presents an outline of the major issues which should be kept in mind by investigators from the very early onset of the program so as to frame it in such a way that it may satisfactorily comply with the multiple constraints, thereby avoiding a waste of time, efforts, and money. While the regulators legitimately require proof of efficacy of the stem cell product and mechanistic insights before granting approval for a human study, their main concern still pertains to safety, particularly for first-in-man interventions. The next section of this chapter briefly summarizes the main cell-related complications that have happened or remain of concern, and which need to be addressed by a risk plan analysis. Finally, stem cells pose unique ethical problems, particularly when one is dealing with human pluripotent stem cells and some general considerations surrounding this ethical debate are presented in the last part of the chapter.