Women's attractiveness has been found to be negatively correlated with waist-to-hip ratio (WHR) in many studies. Two components of this ratio can, however, carry different signals for a potential mate. Hip size indicates pelvic size and the amount of additional fat storage that can be used as a source of energy. Waist size conveys information such as current reproductive status or health status. To assess which of these two dimensions is more important for men's perception of female attractiveness, we used a series of photographs of a woman with WHR manipulated either by hip or waist changes. Attractiveness was correlated negatively with WHR, when WHR was manipulated by waist size. The relation was inverted-U shape when WHR was changed by hip size. We postulate that in westernized societies with no risk of seasonal lack of food, the waist, conveying information about fecundity and health status, will be more important than hip size for assessing a female's attractiveness.