Described is a mathematics-science intervention program for precollege minority students, specifically Chicanos and American Indians. The program is based on the experiences of intervention programs designed to increase the participation of non-minority underrepresented groups in mathematics related careers. It is proposed that in order to maximize the effectiveness of the intervention program activities aimed at impacting teachers, counselors, parents, students, and the school, curriculum should be undertaken on a sustained basis for a long period of time. The involvement of the local community and industry is a necessary ingredient for increasing the effectiveness of these efforts. Also recommended is the inclusion of a sound evaluation program in order to systematically identify the successful activities which can or cannot be duplicated in other geographical localities. (Author/PB)