Abstract: Objective: This study was focused on effects of ozone application on vital and biochemical parameters in rat model of endotoxin-induced shock. Materials and Methods: Lipopolysaccharide (LPS; 10 mg kg–1, i.p.) induced shock model was used in male Wistar albino rats. Three different doses of ozone were used for this study (0.1, 0.3 and 1.0 mg kg–1, i.p.). Tail-cuff method was preferred for measurements of systolic blood pressure and heart rate. Plasma nitric oxide (NO), total antioxidant capacity (TAC), asymmetric dimethylarginine (ADMA), aspartate transaminase (AST), alanine transaminase (ALT) and lactate dehydrogenase (LDH) levels were detected as biochemical parameters. Results: Decline in systolic blood pressure and increment in heart rate of rats were observed an hour after injection of LPS. Ozone application did not possess any significant improvement on impaired systolic blood pressure and heart rate. Increased plasma levels of NO and decreased TAC levels with endotoxemic shock were reversed by ozone treatment. No significant effect on augmentated plasma levels of ALT by endotoxemia was observed with ozone application. On the other hand ADMA, AST and LDH levels were not changed with endotoxemia or ozone application. Conclusion: These results suggested that ozone treatment reversed the LPS-induced changes inplasma NO and TAC levels, but not other vital and biochemical parameters in rat model of endotoxin induced shock.