This study focused on the knowledge and opinions of physicians regarding legal and ethical aspects of abortion. A self-administered questionnaire was filled out by 57 physicians working in the emergency rooms of two hospitals in Ribeirão Preto, São Paulo State, Brazil in 2001. The questionnaire had 38 questions on general knowledge, legislation, and attitudes towards abortion. Interviewees' mean age was 28.3, most were females, 52.6% were single, 42.1% were married, 54.4% were Catholic, and 21% were Spiritists. Although most of the physicians had a good level of overall knowledge on abortion (70%), one in five was not aware that abortion is the main cause of maternal mortality in Brazil. Most accepted the prevailing legal conditions for performing an abortion in Brazil but would also include fetal malformation incompatible with life, while opposing decriminalization of abortion on other grounds. Limited knowledge is revealed by misconceptions concerning enforcement of the prevailing legislation in practice. The study strongly suggests that many physicians lack knowledge or face difficulties in conforming to the Brazilian legislation on abortion.