We examined gender differences in the association between body mass index (BMI) and psychological well-being. Regression analysis involving 3,251 adults indicated that gender moderated the BMI–psychological well-being link. In follow-up analyses, higher BMI predicted lower psychological well-being only among women. When participants were categorized into 5 BMI groups, women reported lower psychological well-being than men in the overweight and obese I groups, but no gender differences were observed in the more seriously obese or normal-weight groups. Also, among women, all 4 groups with higher-than-normal BMI had lower psychological well-being than normal-weight women; for men, no significant differences were found across the 5 groups. These findings are discussed in relation to research on stigma theory and gender-differentiated cultural norms regarding weight.