This article compares the extended family integration of Euro and Mexican American women and men and assesses the importance of class and culture in explaining ethnic differences. Using National Survey of Families and Households II data (N = 7,929), we find that ethnic differences depend on the dimension of integration. Mexican Americans exhibit higher rates of kin coresidence and proximity, but lower rates of financial support than Euro Americans. Two additional differences exist only among women: Mexican American women are more likely than Euro American women to give household or child care help. As to the explanation for these differences, social class is the key factor; cultural variables have little effect. Our findings support a theoretical framework attending to intersections among ethnicity, gender, and class.