Throughout the life cycle, there is a tendency for individuals to increase and/or decrease some personality traits. The present study aimed to compare the magnitude of the Big Five personality traits among adults and the elderly, and to identify the role of sociodemographic variables (age, schooling, sex and marital status) in their personality traits. This cross-sectional study analyzed 151 participants divided into two groups by age. The elderly group was composed of 78 participants between the ages of 60 and 85 years, and the adult group included 73 participants between 30 and 59 years of age. Participants completed a socio-demographic data sheet and the Five-Factor Inventory-short form (NEO-FFI-R). Results revealed significant differences between the groups associated with the factors Neuroticism, Openness, and Conscientiousness. The adult group showed a significantly greater tendency for higher scores in Neuroticism, Extraversion and Openness. In the elderly group, in turn, there was a greater tendency for individuals to score higher on Conscientiousness. In conclusion, adults tended to present elevated levels of factors such as Neuroticism, Openness, and Conscientiousness, while the elderly presented higher Conscientiousness. These results suggest that personality factors are adjusted according to age group and life events.