Introduction. Trauma remains one of the medical and social problems with a major impact on the health of the population, especially affecting young people. Thus, 1.24 million people die annually only in road accidents according to the WHO data. Aim of the study. To study intoxication syndrome in trauma patients with haemoperitoneum during nonoperative management (NOM) by means of evaluation of: necrotic substances (NS) and substances with average molecular weight (SAMW), advanced oxidation protein products (AOPP), advanced glycation end products (AGE) and total antioxidant activity (TAA). Materials and methods. Prospective study (2011-2016) included 59 trauma patients with traumatic haemoperitoneum. Time frame of evaluation of biochemical parameters: at hospitalization, at 3-rd and at 5-7-th days. All trauma patients were divided in 2 groups considering haemoperitoneum volume at admission. Group I with haemoperitoneum volume up to 500 ml includes 38 patients (n¹=38) and group II with haemoperitoneum volume more than 500 ml 21 patients (n²=21). Results. Mean age of the patients was 37.6±15.2 years. M/F ratio: 2.7/1. Trauma scores: ISS=22.9; RTS=7.4; TRISS=90.4%. Mean volume values of hemoperitoneum at hospitalization constitutes 299,74±182,26 ml in group I and 788,1±293,22 ml in group II with values ranging between 0 and 1500 ml. NS mean values in group I: 1.96±0.91; 1.80±0.69; 1.56±0.39 c.u.; in group II: 2.74±2.71; 1.89±0.91; 1.55±0.34 c.u. SAMW mean values in group I: 20.30±8.58; 18.27±6.04; 16.00±3.66 c.u. (p<0,05); in group II: 25.44±21.93; 18.46±5.84; 15.96±3.90 c.u. AOPP mean values in group I: 37.87±20.43; 34.75±17.89; 27.15±13.28 μmol/L; in group II: 32.14±18.61; 28.06±17.33; 24.19±19.52 μmol/L. Mean values of AGE in group I: 503.36±176.30; 476.88±179.10; 457.95±164.69 mmol/L; in group II: 522.67±170.96; 542.33±186.09; 476.66±155.48 mmol/L. TAA mean values in group I: 0.33±0.06; 0.33±0.09; 0.31±0.05 mmol/L; in group II: 0.35±0.07; 0.33±0.05; 0.31±0.06 mmol/L. Conclusions. Intoxication indicators (NS, SAMW) in trauma patients with haemoperitoneum during NOM did not exceed normal range values and did not show any significant differences between group I and II. That can be appreciated as lack of intoxication syndrome in patients with traumatic haemoperitoneum during NOM. SAMW in group II showed statistically significant decrease in dynamic, but the values still not exceeded normal ones. Mean values of AOPP, AGE and TAA did not exceed the values of the normal ranges and, generally, did not show significant differences between both groups or in dynamics, suggesting that antioxidant body system is not affected during haemoperitoneum absorption process.