Background/aims: It was suggested that serum pentraxin 3(PTX3) levels could differentiate obese adults with nonalcoholic steatohepatitis (NASH) from those with simple fatty liver. Our objective was to assess the clinical value of serum PTX3 levels as a diagnostic tool for nonalcoholic steatohepatitis (NASH) and to determine its significance in evaluating the severity of NAFLD in obese adults. Methods:For our study, we recruited 120 Indian subjects who visited the outpatient clinic of Vels medical college and Hospitals between June 2022 and April 2023, presenting with non-specific symptoms. These participants were categorized into two groups based on ultrasound findings: the Control group comprising 60individuals (19 males - 31.6%, 41 females -68.3%), aged between 26 to 50 years, with no evidence of NAFLD, and the NAFLD Group consisting of 60 patients (16 males - 26.6%, 44 females - 73.3%), aged between 20 to 60 years, who had varying grades of NAFLD. Serum PTX3 levels and routine laboratory investigations were conducted for all the subjects. Results: BMI showed a higher significant difference in NAFLD than the control group (34.5+ 9.8 kg /m2 vs. 26.9 + 3.9kg/m2, P<0.001). Also, ALT and AST levels were higher in the NAFLD group than control; ALT(37.4+23.9 mg /dl vs. 25 + 9.6 mg/dl, P=0.001), AST (32.8 + 18.5 mg/dl vs. 24.3+ 11.7 mg/dl,P<0.001) respectively. Serum pentraxin level was statistically significantly higher in the NAFLD group (2.9 ±1.4 ng /ml) vs. control (0.61 + 0.43 ng/ml), (P< 0.001). Conclusion: "Utilizing noninvasive monitoring of serum PTX3 fragment levels in obese patients with suspected NAFLD may offer a dependable approach for distinguishing NASH from simple fatty liver.