BACKGROUND This study examined attitudes towards and knowledge about abortion among undergraduate students doing eleven different subjects. The differences in attitudes and knowledge about abortion according to gender, religious and political affiliation, religiosity, sexual orientation, number of sex partners and previous sexual experience were also considered. METHODS 1,025 undergraduate students (58.34% women and 41.66% men; mean age 20.18) completed the following instruments: an adaptation of the Abortion Attitudes Scale by Hill, and an adaptation of Abortion Knowledge Test by Esposito and Basow. RESULTS With attitudes ranging from 0 to 100, medicine, psychology and nursing students were in the anti-abortion range (55.93, 54.19 and 53.62, respectively) while history, philology and physics students were in the pro-abortion rights range (48.44, 48.49 and 50.12, respectively). Law, medicine and nursing students showed greater theoretical knowledge about abortion, while physics, engineering and philology students proved to be the least knowledgeable. CONCLUSIONS Differences were found in students’ attitudes towards abortion and in knowledge about abortion depending on their degree subject. As in previous reports, differences were found in students´ attitudes towards abortion which reflected differences in religious affiliation, religiosity, political affiliation, and previous sexual experience.