Decisions concerning children in the health care setting have engendered significant controversy and sparked ethics policies and statements, legal action, and guidelines regarding who ought to make decisions involving children and how such decisions ought to be made. Traditionally, parents have been the default decision-makers for children not only with regard to health care but with regard to other matters, such as religious practice and education. In recent decades, there has been a steady trend away from the view that parents are in authority over their children and toward the view that children are rights-bearers who should be granted greater authority over themselves. The mature minor doctrine refers to the decision to grant mature minors the authority to make decisions traditionally reserved for their parents. This essay (1) documents the trend towards expanding the understanding of some minors as "mature" and hence as having the right and authority to give informed consent, (2) examines the reasons for which some commentators have a special interest in expanding the mature minor doctrine to the research setting and allowing minors to enroll in research without parental permission, and (3) defends the view that the mature minor doctrine, regardless of its application to clinical health care decisions, ought to be set aside in the research setting in favor of greater parental involvement.