Data on 174,595 Norwegian women aged 15-44 who had an induced abortion between 1979 (when all abortions through 12 weeks of gestation were legalized) and 1990 reveals that the general abortion rate decreased by 12% among married women, while it remained unchanged among unmarried women. Unmarried women had higher abortion rates than did married women among all age-groups except teenagers, increasing from a difference of 11 abortions per 1,000 women in 1979-1981 to a difference of 13 per 1,000 in 1988-1990. Pregnancy terminations occurred at an earlier gestational age during the last three years of the study period, compared with the first three. Abortions beyond 12 gestational weeks, which require the approval of a hospital committee, decreased among unmarried women, while increasing somewhat among married women. A larger proportion of married women than unmarried women terminated pregnancies beyond 18 gestational weeks.