We used a brief scale to measure student-instructor rapport and assessed the degree to which student's perceived rapport at the beginning, middle, and end of the semester predicted final course grades in a traditional course. Results showed a positive correlation between rapport scores and final grades such that rapport at each of the time points during the semester predicted final course grade. Those students for whom rapport decreased across the semester showed significantly lower final grades than students for whom rapport remained stable or increased. Results support the psychometric properties of the Student-Instructor Rapport Scale-9 and that student-instructor rapport formed early in the semester predicts academic success.