The aim of this study was to review the classical concept of bladder physiology in regard to sex hormone effects and to focus on a new concept. Sex hormones affect bladder functions and the classical concept tries to explain these effects via and adrenoreceptors. The effects of hormones had been investigated in this understanding. To obtain a biological response to steroids in target tissues, specific proteins - so called receptors - are warranted. After the demonstration of the sex hormone receptors in bladder first in adults and in children urge questioning the effects of hormones in this regard. The hypothesis is based on the fact that, if a special receptor is present, the direct (via sex hormone receptors) effect is more likely to occur as an indirect effect (via and adrenoreceptors). There is evidence that there is a sex difference and the sex receptors and hormones play an important role in some bladder disorders. Therefore we stress the importance of investigating especially the pediatric patients with bladder problems in regard to sex hormone receptors and hormonal status. (C) 2002 Elsevier Science Ltd. All rights reserved.