C – Reactive Protein (CRP) is an acute phase protein used to diagnose the presence of inflammation. A rise in CRP concentration in serum may be present in trauma, inflammation, infection, or cancer pathology. Many studies have evaluated severe levels of procalcitonin (PCT) as a prediction in the development of sepsis, infected necrosis. Methods: Levels of PCT and APACHE II (Acute Physiology and Chronic Health Evolution) were assessed on the day of sepsis diagnosis in 160 septic patients after abdominal and thoracic surgery, and in similar number of cases (n≈160). CRP results, pre and postoperatively were recorded, with considerations of comorbidity and surgical procedure. Results: Patients with comorbidity were more likely to have a high CRP. In 68% of patients, during the first 3 days of the postoperative period, CRP was requested. In this study, we observe a CRP peak at postoperative two or three days, and then it fell. In present study, the multivariate analysis shown, that APACHE II score, and PCT level were independent early predictive markers to indicate the severe lethal sepsis. In this study, 70% of the high-risk patients died of sepsis. The predictive power of both parameters (PCT, APACHE II score) in combination was shown to be superior to that of either single parameter. Conclusions: In multivariate analysis, both APACHE II score and PCT were identified as independent and early predictive indicators of sever sepsis, and sepsis lethality. The NICE guidelines do not recommend the usual determinations in preoperative of the CRP, and the postoperative levels of CRP have a limited role to screen the infection. The CRP level can de used in diagnosis of infection after the first three postoperative days. The routine use of CRP in preoperatively and in the first 2-3 days postoperatively is not recommended.