Considerations are put forth with regard to legal aspects of investigation in human beings and the importance of informed consent as established in the general Law of Health. Here in are pointed out legal and ethical dispositions established in the General Law of Health for protection of minors and the disabled. Commentary is presented on importance of information, autonomy, understanding, and freedom of election that are not afforded to those under the legal age and there interfere in minors being included in investigation projects. Diverse ethical aspects are commented on that should be considered throughord the entire investigation.