Objectives: To test neurocognitive function in patients with late-onset Tay-Sachs disease (LOTS) using a computerized system to assess whether cognition is a clinically relevant outcome measure of possible therapeutic intervention in LOTS. Methods: Ten adults with Tay-Sachs disease were administered at least one battery of the Mindstreams Neurotrax system for evaluation of cognitive function. Six sub-scores and a Global Cognitive Score (GCS) were tabulated. A disease specific severity score was also devised with six domains. Results: Despite identical genotypes, all patients but the two oldest had ≥3/6 sub-scores one standard deviation below normal mean (100); verbal and executive functions were most affected. The severity score measured other functions. Conclusions: Because of provocative findings on re-testing in patients exposed to miglustat, and despite the very small cohort, cognitive function may be an appropriate and clinically relevant outcome measure for future therapeutic interventions in LOTS.