This report focuses on the evidence on the health, economic and other benefits of investing in family planning. Family planning allows people to attain their desired number of children and determine the spacing of pregnancies. It is achieved through use of contraceptive methods and the treatment of infertility. A large and growing body of literature explores the social and economic benefits of women’s ability to use reliable contraception to plan whether and when to have children. Compared to other interventions, investments in family planning have been shown to be highly cost effective. It is inexpensive and the return on investment is high. Family planning interventions have powerful poverty reduction effects in addition to providing health and human rights benefits.