Interleukin-6 (IL-6), which is expressed in the human adrenal gland, was found to be a very potent activator of the human HP A axis. So far nothing is known about a local paracrine or autocrine influence of IL-6 within the human adrenal. In this study, the expression of IL-6 and the IL-6 receptor by human adrenal cells in vitro could be demonstrated by immunohistochemistry Possible effects of IL-6 on steroid release were tested by incubating human adrenal cells in vitro wiin IL-6 [10^-8 M]. Adrenal steroids were stimulated by IL-6: aldosterone 184 ± 23, cortisol 198 ± 19, DHEA 140 ± 8 and androstenedione 136 ± 5 (results are means ± s. e. m. in%). In conclusion, IL-6 can act directly on human adrenal cells and appears to be an important paracrine or autocrine factor.