A clinical form of sepsis induced by cecal ligation and puncture (CLP) was caused in order to monitor the concentration of enzymes (alanine aminotransferase -ALT, aspartate aminotransferase -AST, lactate dehydrogenase -LDH, amylase and creatine kinase -CK) in the rat blood. Experiments were performed on male Wistar rats, weighing on average 215±25 g. The rats were divided into four groups. In the first three groups (n=28 per group), sepsis was induced by pure culture of Escherichia coli (EC) or Staphylococcus aureus (SA) and mixed culture (MK) of caecum, while the fourth group included 20 control rats who underwent an abdominal incision. Blood was taken in time intervals of 12, 24, 72 and 120 hours.During the experimental protocol, we identified significant changes of all monitored enzymes in the serum of infected rats. After a period of 12 hours there was a significant increase in ALT (all rats with sepsis), AST and LDH (rats in the MK group) levels, while a decrease was noted in the concentration of amylase (EC, SA). Similarly, 24 hours after the CLP procedure, a significant decrease of amylase (MK) and AST (SA) was recorded, while serum LDH level varied significantly from elevated (EC, SA) to reduced (MC) values. Finally, at the time intervals of 72 and 120 hours the concentration of nearly all monitored enzymes has shown a decline, while significance was noted in lowering of ALT (MK), AST (SA, EC) and amylase (SA) levels. Statistical significance could not be observed in the change of CK levels at any of examined time points.