The accomplishments of Mexican American students have been limited by the level of education completed and by concentration in particular occupations. As part of a larger research project concerning this problem, 259 eighth grade students from Tucson were compared on the basis of sex and ethnicity, with a focus on attitudes toward science. No significant sex or ethnic differences were found in attitudes toward science courses or in social encouragement and expectations. In response to questions on the link between school and future work, Anglo females and Mexican American males perceived science as most important. Mexican American girls rated science as less important for understanding the world than Anglo girls did. In answer to questions about sex roles, girls within each ethnic group were more nontraditional than boys; responses of Mexican American and Anglo boys were not significantly different. Few girls considered science and career education as more appropriate for boys. Implications drawn from the study were: minority students need better preparation in basic skills; students need to be encouraged to take math and science courses; changes in curriculum may be necessary; better career counseling is necessary; and sex-typing of science, math, and careers in general needs to be addressed. (AN)