Based on the Implicit-Affect-Primes-Effort model and evidence that aging is associated with cognitive difficulties, this experiment investigated the effect ofmasked age primes on young adults' effort-related cardiovascular response during a mental arithmetic task.We predicted that elderly primes should activate the aging stereotype and thus render the performance difficulty concept accessible, while youth primes should activate the performance ease concept—similarly, as affect primes do. The accessible difficulty or ease concepts, in turn, should influence experienced demand and thus effort-related cardiovas- cular response during cognitiveperformance.Aneutral prime control condition should fall into these conditions.We found the expected effects on performance-related responses of heart rate (HR) and diastolic blood pressure (DBP): For bothmeasures, the elderly primes led to the strongest reactivity, the youth primes led to the weakest reactivity, and the neutral-prime control condition fell in between these conditions.