The limited empirical data available on maternal health problems among Mexican immigrant women in the United States suggest that they underutilize health services, especially general preventive care. Research conducted among legal and undocumented women in the Mexican immigrant population in San Diego, California, support these findings. Among undocumented mothers, 11.5% of their births in the U.S. occurred with no prenatal care or care sought in the third trimester, which is much higher than Mexican women legally in the country (3.6%) and the general San Diego maternal population (3.8%). When we examine births which occurred within the last five years by immigration status, we find that women legally in the country have a much higher rate of cesarean delivery of both undocumented women and women in the general San Dicgo maternal population. Undocumented women in our sample were much less likely than their legal counterparts (a) to return for postpartum examinations for themselves, (b) lo seek neonatal care for their infants, and (c) to have had Pap examinations or carry out breast self-examinations.