Dual relationships between professors and students have many ethical risks. This article discusses how the professor's role, characteristics of the situation, characteristics of the student, and a set of four decision criteria can be used to assess the risks of dual relationships. The examples of a professor who is involved in a consensual sexual relationship with a student and a professor who has a friend who wants to enroll in his or her class are used to demonstrate how the decision (...) criteria can be applied. Several general characteristics of dual relationships are discussed. (shrink)