Obesity is considered to be the leading metabolic disease in the world. The coincidence of postoperative complications is higher in obese individuals; thus, laparoscopic techniques due to their minimally invasive character became a standard in the surgical treatment of obesity. The proper function of peritoneal tissue is essential for the response to surgical trauma. Therefore, understanding the alterations of peritoneal tissue of obese individuals might explain the increased number of postoperative complications observed in obese patients. The study aimed to assess whether the stability of peritoneum is altered in obese patients and whether it corresponds to early postoperative complications in obese patients. Samples of parietal peritoneal tissue were collected at the beginning of the laparoscopic cholecystectomy from 80 patients. Differential scanning calorimetry was performed on samples defrosted at room temperature. Patients were divided into three groups according to the BMI value. For statistical analysis, ANOVA, Chi-square, Student’s t test, and correlations with Pearson test were used. Significantly lower ΔH and higher Tm were in patients in whom intraperitoneal adhesions were reported. Lower ΔH was reported in samples obtained from patients with temperature above 37 °C in the first 24 h postoperatively. Enthalpy of thermal transition (ΔH) in peritoneum obtained from parous was significantly lower in comparison with the samples from nullipara. It can be concluded that DSC parameters correlated with parameters related to the early postoperative period. Occurrence of adhesions was reported more frequently in the group of obese and overweight individuals and correlated with lower change in enthalpy of collagen denaturation.