Context: Relatively little is known about how poverty and illiteracy affect women's decisions to adopt contraception, specifically their likelihood of never having practiced contraception. Methods: A random sample of 883 women in union aged 15-49 living in the Border Region of the Mexican state of Chiapas were interviewed in 1994 as part of a regional survey of reproductive health. Multivariate logistic regression analyses were performed for the sample as a whole and for individual age-groups to determine the relationship between socioeconomic variables and the likelihood that a woman had never practiced contraception. Results:The lack of any schooling at all was independently associated with the likelihood of nonuse of contraceptives, as illiterate women were 1.6 times as likely as those who attended secondary school to have never practiced contraception. Other socioeconomic variables that also independently raised the likelihood of nonuse were delivering at home, having experienced the death of at least two children and not having paid employment at the time of the survey. The effect of schooling on the likelihood of nonuse varied by age: While never having been to school increased that likelihood among both the youngest and oldest women, the magnitude of the effect lessened over time. Moreover, among younger women, socioeconomic variables other than school attendance were more important in explaining nonuse. Conclusions: The increased availability of family planning services in the Border Region of Chiapas over the last 20 years has weakened the direct effect of schooling on contraceptive practice. However, having never been to school remains a strong predictor of never-use of contraceptives in this population.