Introduction: Awareness of the incidence of abortion in Iran is essential to promoting maternal health. Therefore, it is of paramount importance to estimate the rate of induced abortion. The present study aimed to investigate the rate, causes, and changes associated with induced abortion during 2009-2014. Methods: This survey was conducted using the abortion data collected from two fertility surveys preformed in 2009 and 2014 on a respective sample of 2,934 and 3,012 married women aged 15-49 years in Tehran, Iran. The incidence of abortion was estimated based on the age-specific abortion rate, general abortion rate, total abortion rate, and abortion ratio Results: During 2009-2014, total abortion rate reduced from 0.16 to 0.14 cases per woman, while the general abortion rate decreased from 5.5 to 4.4 cases per 1,000 women, and the annual rate of abortion declined from 11,500 to 11,400 cases. Assuming the estimated abortion rate in Tehran as a national average rate, it is estimated that approximately 101,000 abortions are performed in Iran annually. Moreover, about 9% of known pregnancies are reported to be terminated in Tehran. Mean age at abortion is 33.5±6.3 years, and the rate of induced abortion is comparatively higher among the women with academic education, proper employment, favorable socioeconomic status, and low religious tendencies, as well as the migrants of urban areas and those with no or one living child. The proportion of abortions for non-medical reasons was found to increase from 69% in 2009 to 82% in 2014. In addition, half of the induced abortions were due to withdrawal failure; however, only one-third of the women with withdrawal failure switched to modern contraceptives after abortion. Conclusion: According to the results, the high prevalence of induced abortions in Iran highlights the need for effective family planning services and counseling in order to prevent unintended pregnancies among women. © 2018, Mashhad University of Medical Sciences. All rights reserved.