Background: Studies looking at self-esteem and body size or adiposity generally demonstrate a negative relationship. However, the relationship between the source of self-esteem and body size has not been examined in college women. Purpose: The purpose of this study was to evaluate the relationship of body size and adiposity to source of self-esteem (achievement or self-acceptance) in young adult women. Methods: Participants were healthy women between the ages of 18 and 25 years. Participants completed the Worth Index to determine source of self-esteem. Body height and weight were measured and body composition was assessed by the BOD POD. Results: One hundred fifty-eight college women completed the study. Source of self-esteem was primarily self-acceptance. Achievement self-esteem in appearance was positively correlated to percentage body fat ("P" < 0.05). Body mass index (BMI) was negatively related to self-acceptance self-esteem in appearance and performance ("P" < 0.05). Global self-esteem was significantly lower for individuals in the highest BMI category. Discussion: Women with higher BMI and body fat tend to see their worth as more contingent upon appearance than women with lower body weights. Thus, these women tend to have a source of self-esteem that is less stable and more psychologically vulnerable. Translation to Health Education Practice: Self-acceptance self-esteem contributes to a healthier sense of self than achievement self-esteem. These results help to inform health educators on how to effectively plan health programs for young women.