The article discusses issues of medical experimentation on humans. The authoresses focus particularly on legal conditions of experimental research, simultaneously touching on non-legal aspects (mainly connected with the role of moral norms when establishing bioethical standards). The paper brings up the issue of interpretative controversies referring to the notion of medical experiment alone and it also discusses the influence of experimental research on the development of medical studies. The authoresses analyze legal bases of medical experiments in the light of international and European standards. They focus on the principle of participant's consent as a sine qua non condition for his/her participation in a medical experiment. They also discuss a physician's legal responsibility for damage caused by such an activity. They particularly focus on attempts at establishing model solutions to regulations of the above mentioned issues and they also focus on presenting legal aspects of medical experimentation in Poland.