This study examines the associations between appearance-related, actual-ideal self-discrepancies--from both own and romantic partner's standpoints--and negative affect, body satisfaction, and eating behavior. It extends previous research through studying both genders and the romantic partner standpoint, but its main novel contribution is a systematic comparison between idiographic, participant-generated, and nomothetic, fixed-item measures of appearance-related self-discrepancies. The findings show that these measures cannot be, and should not be, treated as equivalent. The idiographic measures were superior in predicting outcome variables when considering the own standpoint. Nomothetic measures did demonstrate some gender-specific associations, but only from the romantic partner standpoint, and only for women. These findings can be explained with respect to the assessment of accessible, versus available, self-discrepancies. Implications for self-discrepancy and body image theory and research are discussed.