This article examines ethical issues in the use of prejudice-reduction simulations, with specific reference to evaluation research conducted on the BLUE EYES-BROWN EYES activity. Risks to participants, such as coercion, informed consent, and stress, were weighed against the individual and collective benefits of simulation participation. It was concluded that, given specific precautions (e.g., appropriately designed debriefing sessions), it is ethically defensible to have simulation participants experience emotional discomfort in the short term if it is reasonably believed they will achieve grater compassion for others in the long term. Problems arising in the evaluation of prejudice-reduction simulations are discussed. Finally, a research agenda is proposed that calls for addressing intergroup-relations theory in the design of prejudice-reduction simulations.