Aim of the study: Monocytes are a major source for proinflammatory cytokines, like Interleukin (IL)-6, IL-8 and TNF-α. Catecholamines, which are often mandatory in the treatment of sepsis, may influence the cytokine expression of human monocytes. In this study the effect of epinephrine, norepinephrine and dopexamine on the intracellular cytokine synthesis in monocytes was examined. Methods: An in vitro model of gramnegative sepsis was established, measured by intracellular flow cytometry (FACS). The kinetics and dose effect curves of the intracellular cytokine expression were obtained. Immunephenotyping for CD14+ cells and measurement of the intracellular cytokine expression was perfomed by multicolour FACS in a whole blood system. Results: TNF-α was the first cytokine produced by monocytes after stimulation with lipopolysaccharid, followed by IL-8 and IL-6. IL-8 and TNF-α showed the same dose effect curves in regard to the LPS stimulus. The expression of IL-6 and TNF-α was inhibited significantly by epinephrine and norepinephrine (10 µM and 100 µM). Expression of IL-8 was not affected. There was no difference, in regard to the inhibiting effect of epinephrine and norepinephrine. Dopexamine, compared to norepinephrine, lead to a decreased inhibiton of IL-8 at high concentrations (100 µM, 300 µM) (p Conclusion: The cytokine expression follows distinct kinetics. The cytokine expression is mainly decreased by catecholamines, but not all cytokines are affected in the same way. The results of this study show that catecholamines, which are frequently used in the treatment of sepsis, are influencing the intracellular cytokine expression in monocytes.