Globally, 19 million women are estimated to undergo unsafe abortions each year. Age patterns of unsafe abortion are critical for tailoring effective interventions to prevent unsafe abortion and for providing post-abortion care. This paper estimates the incidence and the rate of unsafe abortion among women aged 15–44 in the Africa, Asia (excluding Eastern Asia), and Latin America/Caribbean regions, where a woman is likely to have close to one unsafe abortion by age 44. For developing regions as a whole, two-thirds of unsafe abortions occur among women aged 15–30 and 14% among women under age 20. The age pattern of unsafe abortions differs markedly between regions, however. Almost 60% of unsafe abortions in Africa are among women under age 25 and almost 80% are among women under 30. In Asia 30% of unsafe abortions are in women under 25 and 60% in women under 30. In Latin America and the Caribbean, women aged 20–29 account for more than half of unsafe abortions with almost 70% in women under 30. Over 40% of unsafe abortions among adolescents in the developing world occur in Africa, where one in four unsafe abortions takes place during adolescence. Young (under age 25) women in Africa, those over age 25 in Asia and women aged 20–35 years in Latin America and the Caribbean are in the greatest need of interventions to prevent unsafe abortion and good quality post-abortion care.