Although Mexican Americans consume diets that may protect them against adverse health, dietary advantages may disappear with increased acculturation. This study examined whether the nutrient intake of second-generation Mexican-American women of childbearing age deteriorates compared with that of first-generation Mexican-American women and approximates that of White non-Hispanic women. Data on the absolute and relative intake of eight nutrients were obtained from a 24-hour recall and compared among 475 first-generation and 898 second-generation Mexican-American women, and among 2326 White non-Hispanic women. Although first-generation Mexican-American women were of lower socioeconomic status than were second-generation or White non-Hispanic women, they had a higher average intake of protein; vitamins A, C, and folic acid; and calcium than the other two groups. Whereas the mean adequacy ratio of the eight nutrients studied was highest in first-generation Mexican women, it was lowest in their second-generation counterparts. First-generation Mexican women stand a markedly lower risk of eating a poor diet than second-generation Mexican women, whose nutrient intake resembles that of White non-Hispanic women.