This study analyzes the most frequently recurring personality traits of sex offenders. Following an in-depth study of the literature, we hypothesize that, compared to non-offenders, sex offenders exhibit: 1) higher anxiety, 2) higher likeliness to develop antisocial personality characteristics, 3) higher anger 4) 5) 6) sono le ipotesi che abbiamo aggiunto che devono essere tradotte and 7) poorer control of impulses. Methods: Subjects were 9 male sex offenders and 9 male non sex-offenders. Mean age was 30,89 years (d.s. 14,54) in both groups. Subjects were administered the Italian adaptation of the Minnesota Multiphasic Personality Inventory-2. ANOVA was performed on some scales of MMPI-2. A qualitative comparison among personality profiles in the two groups was carried out. Results: Contrary to our first three hypotheses, no difference was found as to anxiety (ANX), anger (ANG) and antisocial behaviour (ASP) between the two groups. On the other hand, a significant difference emerged as to over-controlled hostility (OH), with sex offenders yielding higher scores, indicating they can properly respond to provocations in most situations, but also that they can occasionally exhibit excessively aggressive manifestations without overt provocation. This last result seems to confirm our hypothesis. Conclusions: Differences between sex-offenders and non-offenders tend to be not so noticeable. The only distinctive trait was seen in the over-control of anger and in unexpected and/or violent bursts of anger. Further research should inquire into this last aspect and the personality traits of sex offenders more thoroughly. Key words. Sex offenders; personality; MMPI-2.