The effect of Catholic schooling on the religious behavior of Mexican American and Anglo American graduates of 3 Catholic high schools in El Paso, Texas was compared with the religious behavior of Catholic Mexican American and Anglo American public high school graduates. Focus was on the following types of religious orientations: (1) doctrinal orthodoxy--an orientation stressing intellectual assent to prescribed doctrines of the Roman Catholic Church; (2) devotionalism--an orientation emphasizing the importance of private prayer or personal communion with God; (3) socio-ethical orthodoxy--an orientation stressing acceptance of the conduct norms prescribed by the Roman Catholic Church; and (4) ritualistic practices such as Mass attendance, reception of Holy Communion, and frequency of Confession. Parental religiousness, sex, and ethnic background were used as independent variables to determine whether they conditioned or otherwise affected the impact of Catholic education on one or both of the ethnic groups. Questionnaires were received from 76 public and 127 Catholic high school graduates. Among the findings were: (1) Catholic education had a more consistent, positive impact on Mexican Americans regardless of sex; and (2) Catholic school Mexican Americans scored higher on the symbolically important, formal ritual practices of Mass, Communion, and Confession. (NQ)