This study examined psychological constructs of acculturation, ethnic identity, and teaching efficacy among 89 Latino in-service teachers serving minority students. Results showed significant differences in these constructs in relation to certification, program taught, and years of teaching. First, bilingual teachers were less likely to be assimilated to White-American culture compared to traditionally/alternatively prepared ESL teachers. Second, traditionally certified ESL teachers were more efficacious in controlling disruptive behavior than alternatively prepared ESL teachers. Finally, higher acculturated teachers were associated with university route and ESL program while low acculturation individuals were more likely to hold alternative certification and teach in bilingual program. Educational implications were discussed.