Objective. To assess the blood serum IL-10 concentration in patients with intra-abdominal infections.
 Materials and methods. Clinical specimens were obtained from 56 patients, suffering intra-abdominal infections of various origin: 24 patients - with postoperative abscesses, 12 - with primary intra-abdominal abscesses, and 20 - with diffuse or local peritoneal collection at the day before surgical intervention, on 2nd-3rd day and on 5th-7th day after it.
 Results. There was no trustworthy difference established between the blood serum IL-10 concentrations in patients with different origin of intra-abdominal infections in perioperative period. The significant difference was established, while comparing concentrations of IL-10 in the blood serum in patients with intra-abdominal infections before and on the days 2-3 and 5-7 postoperatively, and in healthy persons.
 Conclusion. Concentration of the blood serum IL-10 ≥ 6.78 pg/mL in patients with different origin of intra-abdominal infections has significant prognostic significance: sensitivity (92.86%) and specificity (80.65%). Further studies, targeting a specific causative agent of nosocomial infection and the cytokine response, are needed.