https://www.selleckchem.com/products/VX-770.html -26. Complicated cholecystitis (CC) is the severe form of acute cholecystitis (AC). Clinical, radiological, inflammatory, or biochemical parameters are used to predict presence of CC. We aimed to evaluate the Glasgow prognostic (GPS) and modified systemic inflammation scores (mSIS) that are used to predict presence of CC. We retrospectively analyzed data from patients who underwent AC surgery from January 2014 to August 2019. Collected information included age, gender, length of stay (LOS), pathology [as CC or uncomplicated (UCC)], albumin, C-reactive protein (CRP), white blood cells (WBC), and neutrophils (NEU) results. The lymphocyte-to-monocyte ratio (LMR) was calculated. The GPS was calculated using CRP and albumin levels, and mSIS was calculated using LMR and albumin levels, and it was scored from 0 to 2. Among the 593 hospitalized patients, 217 patients underwent AC surgery and were included in the study. Among them, 40.1 % of the patients had CC, 53.4 % were male, and the mean age was 51.76 ± 13.8 years. LOS was significantly longer for CC compared to UCC (p =0.018). Four patients died from CC (1.8 %). The mean CRP, WBC, and NEU levels were not different CC compared to UCC (p =0.821, p =0.84, and p =0.196, respectively). The cut-off values for CC were 103.54 mg/L, 15.18 ×10 /μL, and 11.79 ×10 /μL, respectively. GPS and mSIS were significantly higher in CC compared to UCC (p =0.008, p =0.022, respectively). CRP, WBC, and NEU could be used to predict presence of CC. The combination of CRP or LMR with albumin could be a positive but weak predictor of CC, and it is quick, easy to use, and reliable. HIPPOKRATIA 2020, 24(1) 15-20. CRP, WBC, and NEU could be used to predict presence of CC. The combination of CRP or LMR with albumin could be a positive but weak predictor of CC, and it is quick, easy to use, and reliable. HIPPOKRATIA 2020, 24(1) 15-20. The lack of standardized tools limits the diagnosis οf postoperative