Behavior rating scales are indirect measures of emotional and social functioning used for assessment purposes. Rater bias is systematic error that may compromise the validity of behavior rating scale scores. Teacher bias in ratings of behavior has been investigated in multiple studies, but not yet assessed in a research synthesis that focuses on the role of ethnicity and culture. Teacher bias in ratings of student behavior was investigated through a comprehensive literature review that only included studies with a defensible criterion of true behavior against which to compare rating scores. A final total of 13 studies of teacher bias suggested mixed evidence for bias due to student ethnicity and strong evidence of bias due to teacher culture, particularly when positive stereotypes were violated. Limitations and future directions of research are discussed.