Objective: The aim of the present study was to evaluate a behavior checklist designed to measure individual differences in athletes’ motivation toward cognitive testing. Methods: We developed a motivation behaviors checklist (MBCL) of 26 behaviors with theoretical and anecdotal relevance to motivation toward testing. As part of a sports-concussion management program, 77 college athletes were administered a battery of neuropsychological tests at baseline, including the Vigil continuous performance task, the Computerized Assessment of Response Bias (CARB), and Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). Examiners completed the MBCL based on athletes’ behavior during testing. Examiners and athletes rated athletes’ level of motivation on a 7-point scale. Results: Principal components analysis of the MBCL revealed components related to low motivation behaviors (LMBs) and high motivation behaviors (HMBs) with good internal consistency (a ¼ 0.78 and 0.77, respectively). Scale scores were created for LMB and HMB scales by summing items. LMB was correlated with CARB response variability (r ¼ .32, p , .01), athletes’ (r ¼ 2 .27, p , .05) and examiners’ (r ¼ 2 .58, p , .001) motivation ratings, and ImPACT Visual Motor Speed (r ¼ 2 .24, p , .05). HMB was correlated with Vigil false alarm rate (r ¼ 2 .32, p , .01) and ImPACT Impulse Control (r ¼ 2 .23, p , .05). The two scales were uncorrelated with one another (r ¼ .00, p ¼ .99). Conclusions: Results provide preliminary support for the reliability and validity of the MBCL. Correlational findings suggest that the MBCL measures two orthogonal components of motivation toward testing—low motivation behaviors associated with self and other perceptions of motivation, response variability, and psychomotor speed; and high motivation behaviors related to attentiveness and impulse control.