Abstract Although the terms mentor and thesis advisor (or research supervisor) are often used interchangeably, the responsibilities associated with these roles are distinct, even when they overlap. Neither are role models necessarily mentors, though mentors are role models: good examples are necessary but not sufficient. Mentorship is both a personal and a professional relationship. It has the potential for raising a number of ethical concerns, including issues of accuracy and reliability of the information conveyed, access, stereotyping and tracking of advisees, and the abuse of power. Nevertheless, mentors can be critically important for professional success and are one of a number of elements that affect the responsible conduct of research. In addition, the community as a whole has a responsibility to mentor junior members.