We investigated the relationship of sociocultural influences (SI) promoting thinness (parental, peer and media pressures for thinness, and individual value for modernity), age and body mass Index (BMI) to body dissatisfaction (BD) and dieting in 294 Hong Kong community adolescent girls. We proposed that BD mediated SI's relationship with dieting. In bivariate analyses, all variables were significantly (p < or = .05) related to BD (beta's from 0.14 to 0.59), and, except for modernity, to dieting (beta's from 0.17 to 0.51). In multivariate analyses, peer (beta = 0.32, p < .001) and media pressures for thinness (beta = 0.18, p < .01) bypassed BD and were directly associated with dieting. A culture of thinness appears to be associated with weight loss efforts among girls in modernising cultures independent of BD. Our findings call for public policy to restrict promotion of the impossibly thin ideal, and public education regarding the paradoxical effects of dieting.