PIP: In an effort to determine changes occurring between 1968 and 1978 in the percentage who approved of legal abortion in Canada under 6 possible conditions of pregnancy, a survey questionnaire was mailed to a sequential sampling of 1200 fulltime graduate and undergraduate students at the University of Toronto in the fall of 1968. In the early spring of 1971, 1974 and 1978 questionnaires were mailed to 1300, 2950 and 2985 students, respectively. Response rates were 44% in 1968, 59% in 1971, 52% in 1974 and 53% in 1978. The percentage approving under all 6 conditions increased between 1968 (32.6%) and 1971 (49.8%) but declined to 42.6% in 1974 and 36.7% in 1978. All respondents distinguished between 1 set of conditions (harm to mother's health, possible child deformity, pregnancy from rape) that received high and unchanging approval, and a 2nd set of conditions (out-of-wedlock pregnancy, economic inability to support child, unwanted child) which was given lower and declining approval. The Catholic students made this distinction most emphatically, Jewish and agnostic/atheist students least, and Protestants in between. In 1978 males were significantly less approving than females under "child unwanted" but no different under economic reasons or out-of-wedlock pregnancy. Both sexes were highly approving under the other conditions, although males were significantly less so than females in the case of rape. Coitally-experienced unmarried students were significantly more approving of abortion under the 3 least-approved conditions than were their coitally-inexperienced counterparts.