A three-generational analysis of marriages involving Mexican American in Los Angeles County shows higher rates of exogamy than do earlier studies. Exogamy is higher for women and increases with removal from immigrants status. There is a strong pattern of generational endogamy and a strong suggestion that social distance between generations may be as important as social distance between the ethnic group and the dominant society. Exogamy is more prevalent among higher-status idividuals; with some exceptions, occupation appears to be a better predictor fo exogamy than generation. Generally, the older the groom, the more "Mexican" the spouse, though the pattern is not the same for brides. The findings have implications for assimilation of the Mexican Americans and for understanding processes of assimilation.