In this work we have done, in the Helsinki Declaration, which was recently published in Brazil by the World Medical Association (WMA), we aimed to reveal the issues that could create ethical problems especially for researchers. This declaration, which contains ethical principles related to medical research on humans, has provided considerable guidance to many investigators and researchers since 1964. Complicated advances relate to research involving human studies. When medical research is decided on human beings, the health and the protection of the rights of volunteers must be subject to ethical standards. Otherwise there is a possibility that ethical problems that will be talked about too much.