Considerable evidence suggests female adolescent's attempts at weight loss are associated with increased body fat that occurs during puberty accompanied by a mainstream cultural ideal equating thinness with attractiveness. The purpose of this study was to investigate the contribution of body size, self-esteem, age, acculturation, and athletic status to concern or preoccupation over weight in an understudied population, female Mexican American adolescents. Subjects (N=558) ranged in age from 14 to 18 years and were drawn from four senior high schools located in the Lower Rio Grande Valley region of Texas. Data were gathered through a self-report survey instrument dealing with investigated variables and anthropometric measures to assess actual body size. Results indicated subjects' acculturative status was low, body fatness levels high, self-esteem moderate, and, with the exception of percent body fat, there were no variable differences between athletes and nonathletes. Findings suggest that less acculturated Mexican American adolescent females ascribed to the Mexican cultural ideal body size which is larger than the U.S. mainstream ideal thus their increased weight posed less threat to self-esteem. When it surpassed the cultural ideal, body size followed by self-esteem emerged as the strongest predictors of weight preoccupation. As subjects became more acculturated into the U.S. mainstream, i.e. larger body size less acceptable, their self-esteem declined. No significant association was found between either athletic status or age and preoccupation over weight. Based on the data, the Mexican American adolescent's concern over her weight need not be negative if interventions designed to promote healthful weight control methods are utilized. Provision of culturally appropriate information concerning healthy diets, nutrition counseling, physical activity, and healthy body image could help prevent escalation to extreme weight control behaviors. Keyword(s): health promotion, multiculturalism/cultural diversity