Increasingly, donors and developing country health practitioners are calling for an expanded private sector role in the delivery of high-quality family planning and reproductive health services, but policy guidance on how to encourage greater private sector participation is scarce. As of the mid-1980s, however, Indonesia has been expanding the private sector’s share of the nation’s family planning service provision. In 1987, only 15 percent of women obtained contraception from the private sector; by 1997, the share had risen to 42 percent, marking a nearly three-fold increase. This case study documents Indonesia’s family planning experience with a view to understanding the factors and conditions that led to the remarkable growth in the private sector’s role in delivering family planning services. Indonesia’s National Family Planning Coordinating Board (BKKBN) was instrumental in planning for the private sector’s growth. It successfully generated nationwide demand for family planning, responded to changing consumer preferences over time, supported a new cadre of private sector service providers, and introduced an affordable line of contraceptive products. While Indonesia’s private family planning sector expanded in response to several converging factors, the government’s commitment to promoting the private sector as a source of family planning services was clearly prominent among all factors.