Background and Aim: Gender differences are of intrest to numerous researchers trying to conceptualise psychological well-being. This study was conducted to determine the role of sex discrepancies in psychological well-being scales- adjusting to age as a covariate variable. Materials and Methods: In this descriptive-analytical study, 376 students (158 males and 218 females) filled out Riff’s Scales of Psychological Well-being. Analysis of covariance (ANCOVA) was used to examine gender differences in the scales of psychological well-being (i.e. autonomy, environmental mastery, personal growth, positive relations with others, and purpose in life and self-acceptance). Results: Results of ANCOVA showed statistically significant gender differences in scales of positive relations with others and personal growth. In other words, the results indicated that female students scored higher on positive relations with others and personal growth than male students while, no significant gender differences were found on autonomy, environmental mastery, purpose in life and self-acceptance. Conclusion: The findings emphasize the need to recognize the role of gender differences studying scales of psychological well-being. Implications of these findings are discussed with mental health professionals.