A random survey was conducted using the campus voice mail system among 550 students of Princeton University to determine their knowledge of and attitudes about postcoital contraception (which has been available at the university health center for more than 15 years). The survey elicited a response rate of 82% and included demographic information in the data collected. The results showed that 95% (98% of the undergraduates) of the sample knew about emergency oral contraception (EOC), but 52% of the respondents could not distinguish EOC from RU-486, only 38% knew that the correct time of use was within 72 hours, only 26% knew that EOC was a regimen which used a large dose of combined oral contraceptives, and 25% knew that the effectiveness of EOC is 75%. 54% of the students believed that EOC is associated with unpleasant side effects, and 7% thought there would be serious side effects (this attitude was significantly related to nonendorsement). Only 12% of the students correctly identified the fertile period in the menstrual cycle and understood the timing factors associated with EOC. 80% of the students approved of EOC, and 91% approved in cases of rape. Those who identified themselves as Democrats were significantly more likely to approve, and those who were highly religious were significantly less likely. Ethical concerns were cited by 32% of the respondents, and 57% had health concerns. 84% felt that EOC was readily accessible, but only 43% knew it was available throughout the week. 30% of the students had experience with a situation in which more information about EOC would have been helpful. Regression analysis of these findings revealed that approval was higher among students who knew the ingredients and side effects of EOC, knew of a situation where it would have been helpful, were not religious, and/or were Democrats. Ethical concerns were associated with health concerns, strong religious feeling, Republican affiliation, and a lack of knowledge about ingredients.