Objective The purpose of the study was to investigate the predictability of concussion diagnosis from four neurocognitive modules collected on the sidelines in high school athletes. We hypothesized that each neuropsychological module would be a positive significant predictor of the diagnostic outcome. Methods The study sample included 64 14- to 19-year-old athletes from four high schools in the southeastern Idaho region. Thirty athletes were diagnosed with a concussion and 34 athletes were not diagnosed with a concussion. The athletes were 75% male (N = 48) and 25% female athletes (N = 16). The athletes completed C3Logix (Comprehensive Concussion Management System), a computerized neuropsychological battery, as part of their baseline examination. If the athlete was suspected of sustaining a head injury, a modified C3Logix battery was administered same day which included the Graded Symptom Checklist (GSC), Trailing Making Test B (TMT B), Simple Reaction Time (SRT), and Choice Reaction Time (CRT) modules. Results Results showed that the GSC (M = 19.25, SD = 16.6, p < 0.001), SRT (M = 314.14, SD = 45.02, p < 0.05), and CRT (M = 417.45, SD = 72.46, p < 0.001) postinjury scores and the GSC (13.88 SD = 15.80, p < 0.001), SRT (M = 23.06, SD = 41.35, p < 0.01), and CRT (M = 1.98, SD = 63.37, p < 0.05) change scores were each respectively positive significant predictors of concussion diagnosis. TMT B postinjury (M = 49.44, SD = 13.94, p = 0.08) and change score (M = 0.48, SD = 13.46, p = 0.12) were not significant predictors of concussion diagnosis. Conclusions The clinically significant findings demonstrate that these short computerized neuropsychological tests are able to detect subtle changes following a concussion. Further research is needed to continue to demonstrate the role of computerized neuropsychological tests on the sideline. [ABSTRACT FROM AUTHOR]