The production of cytokines and chemokines, which are involved in cell activation and cell migration in native pieces of peritoneum, was measured to Investigate immune regulatory reactions in the human peritoneum, The samples were obtained during abdominal surgery and cultured immediately afterwards. In order to test therapeutic options in vitro, the effect of IL-10 and IFN-gamma on the cytokine and chemokine production was also studied. The chemokine monocyte chemotactic protein-1 (MCP-1) was produced and released spontaneously. When lipopolysaccharide (LPS) was added, MCP-1 production increased. In addition, TNF-or production was induced by LPS, When IL-10 was added, LPS-stimulated TNF-alpha production was reduced towards baseline levels, LPS-induced MCP-1 production was reduced by 37%, IFN-alpha did not affect LPS-induced.TNF-alpha and MCP-1 production, but increased baseline MCP-1 production, It can be concluded that short-time culture of native human peritoneum is a method to investigate peritoneal chemokine and cytokine production in patients undergoing abdominal surgery. Further studies are intended to detect cytokine patterns which identify patients at risk of developing peritonitis, In addition, the effects of medications may be tested in vitro in order to investigate options for preventive modulation of the peritoneal immune response in such patients.