Clinicians have questioned the need to obtain annual baseline neuropsychological tests in high school athletes. If no difference among academic grades exists, annual baseline testing may not be necessary. To examine differences at baseline testing on pencil-and-paper neuropsychological tests among grade levels in high school athletes. Cross-sectional, between-groups design. Schools participating in a Georgia high school athletics association. High school football players (n = 198) in the 9th through 12th grades, with a mean age of 15.78 +/- 1.16 years. Participants were divided into 4 groups by grade and were administered a symptom checklist and brief neuropsychological test battery. Grade level served as the independent variable. Symptom and individual test scores within the neuropsychological test battery served as dependent variables. Differences were noted among grades on the Trail Making Test A (F(3,194) = 3.23, P = .024, eta(2) = 0.048), Trail Making Test B (F(3,194) = 3.93, P = .009, eta(2) = 0.057), Symbol Digit Modalities Test (F(3,194) = 4.38, P = .005, eta(2) = 0.064), dominant tap (F(3,194) = 3.14, P = .026, eta(2) = 0.046), and nondominant tap (F(3,194) = 4.902, P = .003, eta(2) = 0.070). Using the Bonferroni correction (P <or= .00625), we found differences between the 9th grade and 11th and 12th grades. Baseline neuropsychological test scores in high school athletes improved as a function of age, with differences between the 9th grade and 11th and 12th grades. Because the differences were driven by 9th-grade test scores, baseline testing should be completed, at minimum, upon entrance into 9th and 10th grades; however, annual testing is still recommended until additional research is conducted.