The Five-Factor Model of personality has been applied to study sexual offending and also been used in the study of how aging affect to personality. The main goal of this study was to study changes seen in personality domains across the life span for a cohort of convicted child molesters. The total sample comprised 169 men convicted and incarcerated for “hands-on” contact sex offences against children. The participants were categorized into three groups based their age: <30 years, between 30–50 years and>50 years. The NEO-Five-Factor Inventory was used to assess personality in these age cohorts. The analysis conducted showed that Extroversion and Conscientiousness differ over age, whereas Neuroticism, Openness and Agreeableness do not. These results suggest that Neuroticism, Openness and Agreeableness domains in child molesters do not varies in the age cohorts studied, whereas Extroversion and Conscientiousness domains experience similar changes to those occurring in general population according with previous studies. As conclusion, in child molesters the influence of intrinsic maturation processes can be seen more clearly for the Extroversion and Conscientiousness domains, whereas are discussed why Neuroticism, Openness and Agreeableness levels do not change across age in the direction expected in this cohort.