In recent years, we have seen a new concern with ethics training for research and development professionals. Although ethics training has become more common, the effectiveness of the training being provided is open to question. In the present effort, a new ethics training course was developed that stresses the importance of the strategies people apply to make sense of ethical problems. The effectiveness of this training was assessed in a sample of 59 doctoral students working in the biological and social sciences using a pre–post design with follow-up and a series of ethical decision-making measures serving as the outcome variable. Results showed not only that this training led to sizable gains in ethical decision making but also that these gains were maintained over time. The implications of these findings for ethics training in the sciences are discussed.