Glucocorticoids suppress many functions in activated monocyte/macrophages, including the release of TNF-alpha. This is likely to contribute to the efficacy of glucocorticoids in some inflammatory diseases, such as rheumatoid arthritis, where TNF-alpha contributes to pathogenesis. Glucocorticoids suppress the activity of reporters which include TNF-alpha promoter regions and modify the activity of NF-kappa B family transcription factors in activated human monocytic cell lines, suggesting effects of glucocorticoids on TNF-alpha gene transcription. In addition, glucocorticoids have been reported to antagonise the enhanced translational efficiency of TNF-alpha mRNA which occurs at least after stimulation of murine monocytic cells. It is likely, therefore, that glucocorticoids act at several points in stimulated monocyte/macrophages to reduce TNF-alpha secretion. Understanding glucocorticoid control of TNF-alpha secretion may explain some of the variability in response to GC in inflammatory diseases and may reveal means of inducing glucocorticoid-like anti-inflammatory effects in monocyte/macrophages without exposing other tissues to the adverse effects of glucocorticoids.