Asian-Americans' exceptional academic achievement has generated a great deal of interest on the part of educators in search of explanations for the phenomenon. In particular, Asian-Americans' mathematics achievement has been remarkable and many studies have found these students outperforming students from other ethnic groups. A study was conducted in the five middle schools of a multicultural school district in a major metropolitan city in the Central South region of the United States. The school district was selected because of the relatively large enrollment of Asian-Americans among minority students (about 20.4% were Asian-Americans). A stratified sample of 1,200 Asian-Americans and 1,200 Anglo-Americans were randomly selected to be included in the study. Three standardized instruments--"Multidimensional Motivational Instrument,""Classroom Environment Scale," and "Instructional Learning Environment Questionnaire"--were adapted for use in this study. Results indicate that there are significant main effects of ethnicity, gender, and grade on middle school students' motivation and perceptions of learning environment in mathematics. Asian-American students reported greater pride in their classwork, stronger desire to succeed, higher expectations to do well in mathematics; but the students has significantly lower affiliation than Anglo-American students. Contains 46 references. (MKR)