This study examines whether the passage of California's Proposition 187, a proposition designed to restrict undocumented immigrants from using public services, had a negative effect on the use of prenatal care and birth outcomes. Comparisons of prenatal care use and birth outcomes before and after the passage of the proposition are made between low-education foreign-born and U.S.-born mothers using California's Birth Public Use files. Multivariate linear and logistic regressions were used to control for regional and maternal characteristics. We find a significant but small decline in the use of prenatal care by low-education foreign-born women after Proposition 187 passed; however, there was no detectable deterioration of birth outcomes. Whether future reductions in the availability of prenatal care would damage the health of children is unclear.