Objective: The ImPACT neuropsychological concussion test battery recently migrated from a stand-alone computer desktop version to a web-based version, with the same neuropsychological measures, symptom questions, and demographic information obtained in each version. However, no published data has been presented that documents the similarity between the two forms. Method: This study compared 142 male and 45 female college athletes, each of whom had been administered both forms as part of their athletic department’s pre-season protocols. As this was a convenience sample, the median length of time between testing was 2 years with a range of 0.5 to 5 years. Bivariate correlations and ANOVA of composite test scores were used across gender to determine the relationship between scores of the two versions. Results: Correlations between the composite test scores for the two versions (by gender) were significant. ANOVA revealed significant differences between versions on the male Reaction Time composite scores, with a trend towards significance in the female sample. Conclusions: These data indicate that the two versions of ImPACT are indeed similar in their output, even with a median of 2 years between tests, except for the Reaction Time test which showed significant differences from time 1 to time 2 for males. Reaction time scores are likely more susceptible to state effects and thus would not be expected to be as stable across versions, and possibly across testing sessions. The trend towards significance in the female sample suggested that a larger sample might reveal the same difference.