The enzyme group of matrix metalloproteinases (MMPs) and their inhibitors, so-called tissue inhibitors of matrix-metalloproteinases (TIMPs), are crucial mediators responsible for wound repair after parenchymal damage. Little is known about the role of MMPs and TIMPs in severe sepsis. The aim of the present study was therefore to investigate their levels in patients with severe sepsis and to examine their association with prognosis. MMP-2, MMP-9, TIMP-1, TIMP-2 and interleukin-6 (IL-6) plasma levels were measured by ELISA methods in 37 patients on day 1 of severe sepsis. 37 healthy volunteers served as controls. Levels of MMP-9, TIMP-1, TIMP-2 and IL-6 in septic patients were significantly higher compared to healthy controls (p<0.001), whereas MMP-2 levels were not different in patients and controls. TIMP-1 levels were significantly higher in non-survivors (4675+/-435 ng/ml, mean+/-SEM) compared to survivors of severe sepsis (3201+/-249 ng/ml; p<0.01). Septic patients with TIMP-1 values >3200 ng/ml were 4.5 times more likely to die than patients with lower values (RR = 4.5; 95% CI 1.14-17.6, p = 0.014). Our results indicate that MMP-9, TIMP-2 and TIMP-1 are elevated in severe sepsis. Furthermore, TIMP-1 may serve as a useful laboratory marker to predict the clinical outcome of patients presenting with severe sepsis.