The study was undertaken to systematically explore some of the social mechanisms within classrooms that mediate educational effects of schools for Mexican Americans in a metropolitan context. Seventy-two teachers from 9 schools in 3 distinct ecological areas in El Paso, Texas, were asked to complete a questionnaire and the Minnesota Teacher Attitude Inventory in order to learn about their academic backgrounds, experience, instructional practices, and attitudes toward special programs for Mexican American students. The instructional process was analyzed by observing and recording classroom behavior. All of the classrooms studied were found to be highly teacher-dominated with little student-initialed discussion. However, differences in teachers' attitudes and classroom approaches were apparent at all grade levels and in all 3 areas. These included affective relations with students, directness in the classroom, and amount of empathy for Spanish-speaking students. The findings indicated that the 2 factors which profoundly affected teacher-student relationships in classrooms were the professional training of the teacher and the peculiar characteristics of the school's student body. Tables and figures are included. (CM)