Indonesia's family planning program is regarded as a major success.Survey data from 1997 reveal that rates of contraceptive use vary dramatically amongIndonesia's 27 provinces, from a high of 67 percent of ever married women currently using contraceptives in the province of North Sulawesi, to a low of 19 percent current users in East Timor and28 percent in Aceh. This study uses both a quantitative analysis of the 1997 Indonesia Demographic and Health Survey, and a qualitative study carried out in July of 2000 to understand regionalvariation. The study identified a small number of factors that show a clear relation with levels of contraceptive use. Media exposure and education are the strongest and most consistent predictors of levels of contraceptive use, and appear to be the surest strategies for promoting family change. But the study also showed that the process of social change is subjectto culturally and historically specific local factors whose presence and importance is difficult to predict. Our study of regional variation in contraceptive use illustrates the range and complexityof obstacles faced by Indonesia's leaders in attempting to forge a single nation fromsuch a diverse and far-flung population. Although the creation of Indonesia in the space of just half a century is a monumental achievement, the project is clearly not yet complete.