Personality traits can affect eating behaviors, the development of obesity as well as obesity treatment failure. We investigated the personality characteristics and their relation with disordered eating in 586 obese women consecutively seeking treatment at eight Italian medical centers (age, 47.7±9.8 years) and 185 age-matched, normal weight women without symptoms of eating disorders (Eating Attitude Test<20). The assessment included anthropometry, the Temperament and Character Inventory (TCI), the Binge Eating Scale (BES) and the Night Eating Questionnaire (NEQ). Logistic regression analyses were carried out in different models with BES score≥27 and NEQ≥30 as dependent variables and TCI scores as independent factors. Personality traits of obese individuals included significantly lower self-directedness and cooperativeness on TCI. BES and NEQ scores were higher in obese women, and values above the defined cut-offs were present in 77 and 18 cases (14 with high BES), respectively. After controlling for age and BMI, high BES values were associated with high novelty seeking and harm avoidance and low self-directedness, the last two scales being also associated with high NEQ. We conclude that personality traits differ between obese patients seeking treatment and controls, and the presence of disordered eating is associated with specific personality characteristics.