Context: Approved Clinical Instructors (ACIs) are integral to athletic training students' professional development. ACIs evaluate student clinical performance using assessment tools provided by educational programs. How ACI ratings of a student's clinical performance relate to their clinical grade remains unclear. Objective: To examine relationships between ACI evaluations of student clinical performance using an athletic training-specific inventory (Athletic Training Clinical Performance Inventory; ATCPI) and the student's clinical grade (CG) over a clinical experience. Design: Correlational. Setting: Large metropolitan university. Participants: 48 ACIs (M=20; F=28; Certified for 7.5+3.2yrs; ACIs for 3.2+1.5yrs) evaluating 62 undergraduate students (M=20; F=42). Interventions: ACIs completed the ATCPI twice (mid-semester, and end-of semester) during their student's clinical experience. The ATCPI is a 21-item instrument: Items 1-20 assess the student's clinical performance based on specific constructs (Specific) and item 21 is a rating of the student's overall clinical performance (Overall). ACIs also assigned students a clinical grade (CG). Pearson product-moment correlations examined relationships between Specific, Overall, and CG, with separate paired t-tests examining differences (p<0.05). Main Outcome Measures: The ATCPI used a 4-point Likert-type scale anchored by 1 (Rarely) and 4 (Consistently), and CG (A=4, B=3, C=2 D =1, 0=F). Results: Two-hundred and sixty-six ATCPI instruments were completed over 4 academic years. The ATCPI demonstrated acceptable reliability (Cronbach's alpha=0.88). All three measures were positively correlated (Specific and Overall, r(264)=0.65, P <0.001; Specific and CG r(264)=0.63, P <0.001; Overall and CG r(264)=0.55, P<0.001). N0o differences existed between Specific (3.5±0.4) and CG (3.5±0.7; t=0.60, P =.55). However, Overall (3.6±0.7) was significantly higher than both Specific (t=-3.45, P<0.000) and CG (t=2.05, P =0.04). Conclusions: ACIs reliably assessed students' specific clinical performance and provided a relatively accurate grade. However, since the overall scores were higher than specific item scores, ACIs overestimated students' overall clinical performance. Additional research is necessary to examine the ATCPI as an assessment tool across multiple institutions and to determine how other variables affect ACI assessments of student performance.