Objectives: The purpose of this study is the evaluation of how the decline of cognitive abilities caused by aging is moderated by biologically determined personality dimensions: Neuroticism (N) and Extraversion (E). Materials and Methods: The research was conducted with the participation of 160 men in good physical health, professional drivers, aged 20–70 (Mean = 40, SD = 11). Personality traits were measured using Eysenck’s Personality Questionnaire — Revised (EPQ-R), while Ravens Progressive Matrices, Go/noGo Task and Peripheral Perception Test were used to evaluate cognitive processes. The score of Ravens Progressive Matrices was treated as a control variable. Results: The results of the study, based on a Hierarchical Multiple Regression Analysis, indicate that besides the intelligence level, age is the best predictor of cognitive functioning level and that this infl uence is additionally moderated by the N trait level as well as, less frequently, by the interaction of age and E. Conclusion: This means that high N trait level increases the infl uence of age on cognitive functions decline. When the N trait level was low, the age differences in measures of cognitive performance were not signifi cant. Thus, the level of N trait may play an important role in the process of cognitive aging. The results are discussed in the context of a driving safety research.