Personality disorders are a topic of ongoing interest. Their assessment and treatment are controversial and there is a lot of work still to be done in both areas. The aim of this study is to present certain psychometric characteristics of the “Cuestionario Exploratorio de Personalidad-III” (CEPER III) (Exploratory Questionnaire of Personality-III), which assesses different styles of personality based on the diagnostic system of the DSM-IV-TR (APA, 2000), but without necessarily assuming a pathology or adjustment problems. The results of the study show an internal consistency for the CEPER-III of 0.97 (Cronbach’s alpha), as well as for its component scales (from 0.75 up to 0.89), its reliability (Guttman = 0.93) and the convergent validity of the styles (from r= 0.50 to r= 0.72) using as criterion the personality disorder sub-scales of the “Millon Clinical Multiaxial Inventory-III” (MCMI-III; Millon, 1994). Sex differences appear in only six of the 14 styles of personality in CEPER-III (five of them confirmed by the same differences as in the case of personality disorders). In short, the CEPER-III may be a good way of measuring behavioral trends in both patients and non-patients, based on the diagnostic symptoms of the DSM-IV-TR.