The aim of this paper was to examine associations between personality traits, eating disorder (ED) behavior, exercise, and gender. The participants (n=1482: 905 women and 577 men) were students from four universities in Norway. The subjects filled out a compound questionnaire including demographics, weekly hours of exercise, type of sport, Karolinska Scales of Personality (KSP), and the Eating Disorder Inventory (EDI). Because of the data collection procedure, it is difficult to provide a clear-cut response rate in this study. The results showed that the risk ratio for women who scored 40 or higher on the EDI was three times higher compared with men. ED behavior did not seem to be associated with high weekly hours of physical activity in general. There were significant gender differences in personality traits. However, women and men with high scores on the EDI showed no differences on the KSP scales, except on "detachment" and "indirect aggression". The most important predictors for weekly hours of physical activity were the EDI scales "drive for thinness" and "body dissatisfaction", and the personality variables "extraversion" and "neuroticism". The factors that contributed most to the differences between students who scored 40 or higher on the EDI and those who scored below 40 on the EDI were neuroticism, BMI, gender, and age.