Dehydroepiandrostreone (DHEA) is a neuroactive steroid produced by the inner layer of the adrenal cortex close to the adrenomedullary cells. Chromaffin cell growth and proliferation are under the control of insulin-like growth factor II (IGF-II) and basic fibroblast growth factor (bFGF). The aim of the present study was to examine the role of DHEA on chromaffin cell proliferation induced by IGF-II and bFGF. In our model, DHEA significantly decreased IGF-II-induced proliferation by 48.7%, whereas it did not affect the proliferation induced by bFGF. These data suggest that DHEA exerts a paracrine function in the control of chromaffin cell growth.