The aim of this study was to monitor plasma interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-alpha), levels in patients with sepsis, septic shock and multiple organ dysfunction syndrome admitted to the intensive care unit. The patients obtained adequate supportive therapy. Plasma samples were taken upon admission, then on days 1, 2, and 5 following admission. IL-6 and TNF-alpha levels were determined using bioassays (7TD1 and WEHI-164.13 indicator cell lines, respectively). The results showed that the kinetics of the cytokine release in septic patients differed significantly between survivors and nonsurvivors. In survivors IL-6 concentrations were initially high, fell down rapidly on day 1 after admission, and persisted very low throughout the monitoring time. In contrast, relatively low IL-6 levels in the nonsurvivors, registered upon admission, rose significantly with peak values on day 3 of observation, declining thereafter. TNF-alpha levels were initially higher in survivors than in nonsurvivors, declined on day 1 following admission, and on day 5 they were higher than the initial values. In nonsurvivors, on the other hand, the starting concentrations of TNF-alpha were much lower than in survivors with a peak on day 3 with a tendency to fall on day 7. The profiles of cytokine production by traumatic patients (90% survivors) revealed low and progressively diminishing levels of IL-6, contrasting with constantly increasing concentrations of TNF-alpha within the monitoring period. We conclude that high IL-6 levels in septic patients accompanied by high TNF-alpha levels may indicate bad prognosis. In contrast, rapidly diminishing serum IL-6 levels, even in the presence of high TNF-alpha levels, could indicate a very good chance for survival. Similar conclusion can be drawn from the monitoring of cytokine production in traumatic, nonseptic patients since almost all of them recovered. We also speculate that TNF-alpha presence in circulating blood is essential for regeneration of tissues and wound healing.