The harmful effects of female genital mutilation (FGM) on women are recognized worldwide. Although it is practiced by persons of all socioeconomic backgrounds, there are differences within countries and between communities. The aim of this study was to use the 2003 Nigeria Demographic and Health Survey data to determine the spatial distribution of the prevalence of FGM and associated risk factors. Data were available for 7,620 women; 1,673 (22.0%) interviewed had had FGM and 2,168 women had living children, of whom 485 (22.4%) daughters had undergone FGM. Unmarried women were more likely to report a lower prevalence of FGM. Modernization (education and high socioeconomic status) had minimal impact on the likelihood of FGM, but education plays an important role in the mother's decision not to circumcise her daughter. It follows from these findings that community factors have a large effect on FGM, with individual factors having little effect on the distribution of FGM.