Low-income women's histories of pregnancies, their use or nonuse of contraception, and their marital status showed racial and ethnic differences in family formation patterns and fertility control practices. Data were analyzed from a survey of 918 low-income women in Los Angeles County. The sample contained about equal numbers of non-Hispanic whites, blacks, and Hispanics. The use of stratified samples equalized the poverty-level composition of the three racial and ethnic groups. First pregnancies for white and black women resulted primarily from nonuse of contraception while unmarried, but almost half of first pregnancies among Hispanics were intentional. Marital dissolution following pregnancy or childbearing was common among low-income whites and blacks, but Hispanics were more likely to have an intact marriage along with a higher average parity. Analyses of histories of pregnancies while controlling for demographic characteristics showed that racial and ethnic differences in rates of different types of pregnancies (classified as intended, accidental, or unprotected) and rates of abortion did not remain significant after adjustment for respondent characteristics and years of exposure to possible pregnancy. Actual parity, however, remained significant when these factors were controlled. Thus, results document distinctive patterns of family formation for low-income women in racial and ethnic subgroups of this population. Implications of these patterns of family formation for economic well-being are discussed.