Objective:To observe the effects of a single dose of 5-fluorouracil(5-Fu) on multiple organ functions and the survival time of rats with multiple organ dysfunction syndrome (MODS). Methods: The study adopted the methods of multiple fractures + scald + Pseudomonas aeruginosa infection to produce the model of SD rats with acute MODS. The rats were randomly divided into MODS model group(n = 36) and treatment group (MODS model+5-Fu,n = 26),each being divided into four subgroups. The rats were sacrificed 24,48,72 or 96 h after the models were built successfully,blood samples were collected to examined the leukocyte numbers of peripheral blood,the leukocyte function,liver and kidney function and myocardial enzymes. Rats’ mortality rate was observed as well. Results: Compared with MODS model group,5-Fu restrained the leukocyte numbers of peripheral blood in the early and middle stages. 5-Fu had no effect on leukocyte respiratory burst but reduced the CD11b expression. During the experiment,rats’ mortality rate of 5-Fu treatment group decreased significantly. There were no differences in serum activity of alanine aminotransferase,aspartate aminotransferase,creatine kinase,creatine kinase isoenzyme,and no differences in blood urea nitrogen between the two groups. The blood glucose level were improved at different stages of 5-Fu group,but increased progressively in contrast group. Conclusion: A single administration of 5-Fu may protect rats with MODS against systemic injury.