We report the results of a randomized trial to assess the impact of an innovative ethics curriculum on the knowledge and confidence of 85 medical house officers in a university hospital programme, as well as their responses to a simulated clinical case. Twenty-five per cent of the house officers received a lecture series, 25 per cent received lectures and case conferences, with an ethicist in attendance, and 50 per cent served as controls. A post-intervention questionnaire was administered. Knowledge scores did not differ among the groups. Confidence regarding ethical issues was significantly greater in the aggregate intervention group compared to the control group. Confidence regarding procedural issues related to ethics was significantly higher for the EI group than for the controls. Responses to a simulated case showed that significantly fewer house officers in the EI group would intubate a patient for whom such therapy would be futile. We conclude that ethics education can have an impact on house officers' confidence and their responses to a simulated case, and that the EI was more effective than the LI. Such results have implications regarding the implementation of ethics education during residency.