Body esteem is the affective aspect of body image, which is shaped by social experience. Compared with men, women have a more negative body image, which is more frequently correlated with depression and dysfunctional thoughts, especially in the case of eating disorders. The purpose of the present study was to examine gender differences in body esteem and its subcategories, and to find out whether there exists a stronger link between negative body esteem and higher levels of dysfunctional thoughts in women. The relationship between body esteem, dysfunctional thoughts and mental illness was examined. Participants were 73 college students doing social sciences and sports training educations. Body esteem questionnaire and dysfunctional thoughts questionnaire as well as a self made questionnaire on mental illness were used. Results showed that women had a more negative body esteem compared to men, especially considering weight. In women, there was a medium-strong negative relation between body esteem and dysfunctional thoughts. The results indicate that the norms for female body ideal that abound in the Western society have a negative affect on women's thinking and body image. Key words: Gender, body esteem, dysfunctional thoughts, mental illness.