Abortion is a public health concern because of its impact on maternal morbidity and mortality. Each year, about 79 million unintended pregnancies, excluding miscarriage, occur worldwide. More than half of these unintended pregnancies end in abortion. The purpose of this study was to determine the ever-event incidence of abortion (spontaneous and induced) and some related factors in a population-based sample of reproductive age women. From July 2003 through January 2004, 2470 women were included in the study through multistage random sampling and were interviewed. Data were collected using a checklist with questions about demographics and specific items regarding abortion history. Information about age, literacy, gravidity, marriage age, abortion, type of abortion, family history of abortion, history of family marriage, smoking, drug use, alcohol use, coffee intake, and incidence of abortion during the previous year were recorded. Statistical analysis included Student's t-test, Chi-square, ANOVA, and logistic regression using SPSS software. Out of the 2,470 women in the study, 775 (45.7%), had at least one abortion in their lives. Of the women who had an abortion, 20.6% reported induced abortion and 74.2% reported spontaneous abortion. Forty-one point four percent of women aged 45 years and older had at least one abortion in their lifetime. Fifty-one (2.1%) women had a history of abortion during the previous year; the largest proportion was 5.4% for the age group 15 - 24 years. The most common method of induced abortion in the previous year was dilatation and curettage (42 to 67%). In multivariate analysis, household number, coffee consumption, gravidity, smoking, and history of abortion in the family were the most important factors related to abortion in the different age groups of women. This study shows that the occurrence of at least one abortion in the life of women in our setting is high and varies by age group. There is a need for expanded comprehensive sexual and reproductive health services, and more education and accessibility of contraception methods.