The use of human and animal subjects in the field of biomedical research is universally accepted. Without such methods, we are told, what would happen to scientific progress and the relief of suffering in the world? Be that as it may, one fact remains: by its very nature, experimenting on human beings and nonhuman animals demands that we protect those who are the subjects of those experiments. In Canada, what kind of protection is offered to human and animal subjects? In the absence of federal legislation, and in place of it, voluntary systems of control have been put in place by the scientific community. These systems are based on the establishment of institutional ethics committees. They are complemented by an a posteriori control of experiments. In this article, the authors describe and analyze these sytems of control. Indeed, although they appear to be reassuring, these systems nonetheless reveal certain weak points.