As active members of the scientific community, graduate students make ethical judgments about the conduct and presentation of their research. Pressures in the research environment often influence these decisions. Because inappropriate decisions can lead to unethical behavior and scientific misconduct, it is important that students understand the resources available to them and learn to analyze and resolve conflicts that are likely to arise in the course of their studies. We describe an approach to integrating practical, peer-led, ethics training into the orientation process for incoming chemistry graduate students. We used a series of case studies drawn from the experiences of senior graduate students to provide the incoming students with a vehicle for discussing relevant moral concerns. In these discussions, we emphasized deciding upon an appropriate course of action and evaluating its practical and ethical consequences. We discuss our experiences, the case studies, and student response to these sessions.