A number of empirically validated theories account for the relationships between factors of achievement motivation and academic performance. However, there is very little understanding of what Asian English language learners' (ELLs') motivational beliefs are in terms of their academic abilities or how much they value subject matters studied in schools compared to Non-Asian groups. This study examines both math achievement and motivational beliefs in science and math among non-Asian and Asian groups classified on the basis of their ELL status. The study uses data from a High School Longitudinal Study of 2009 that was undertaken in the United States. The final sample consisted of 13,175 native English-speaking students and 1180 ELLs. Two-way factorial ANOVA and standardized effect sizes were undertaken to examine mean differences among the groups. Asians' group's mean scores in math achievement were higher than their respective Non-Asian counterparts. In the context of achievement motivation, all Asian groups had a relatively higher level of competence, interest, and utility in both math and science than Non-Asian groups. While the Asian groups, in general, showed between-domain differences (math and science) with respect to their confidence in doing well, the Non-Asian groups indicated between-domain gap for the utility provided by math and science. Although part of the reason for American Asian ELLs' higher math achievement in the U.S. could be attributed to their motivational beliefs, their attitudes toward the subject matters seem incongruous compared with Asian students in Asia.