Background/Context: Past research has examined many factors that contribute to the black-white achievement gap. While researchers have shown that teacher perceptions of students' academic ability is an important contributing factor to the gap, little research has explored the extent to which teacher perceptions of students' academic ability are sustained over time or the extent to which teacher ratings of students' social and behavioral skills are related to their perceptions of academic ability. The current study focuses on whether teacher perceptions of students' academic ability and social and behavioral skills differ by student race and the extent to which ratings at the beginning of the school year explain racial differences in perceptions of academic ability at the end of the year. Purpose: There are two research questions addressed in this study: (1) To what extent do kindergarten teachers rate black and white students' academic ability and social and behavioral skills differently? And (2) to what extent do test scores, fall teacher perceptions of students' academic ability, and social and behavioral skills explain racial differences in teacher evaluations of students' academic ability in the spring of kindergarten? Population: This study uses the Early Childhood Longitudinal Study-Kindergarten Cohort of 1998-1999 (ECLS-K) kindergarten fall and spring data. The analytic sample used in this study includes students who were in both kindergarten waves with the same teacher and who were identified as black (2,494) or white (9,891) as reported by their parents. Research Design: This is a quasi-experimental study that uses two data points from kindergarten (fall and spring). Mean differences are used to answer the first research question, and teacher fixed-effects models are used to address the second research question. Conclusions/Recommendations: This study finds that teachers perceived black students to have lower academic ability in fall and spring of kindergarten compared to white students as well as lower levels of social and behavioral skills. Teachers' fall perceptions have lasting implications for how teachers perceive their students in the spring, and this appears to have more negative consequences for black students. Teacher reports of social and behavioral skills are more important for teacher perceptions of student ability for black students than for white students. In other words, behaving well for black students has a larger influence on teacher perceptions of students' academic ability than it does for white students.