Background & Objective: An acute deterioration of liver function in a patient with previously compensated chronic liver disease is a result of relentless progression of underlying liver disease. This research was conducted to elucidate clinical profile, precipitating factors, prognostic factors, predicting the survival and outcome of Acute-on-chronic liver failure in cirrhotic patients. Methods: This prospective observational study of hundred patients was conducted in PVS Memorial Hospital, Cochin, Kerala, India in 2015-16. Patients were followed up during hospital stay and outcome was noted at 28 day. The clinical manifestations, laboratory parameters and other imaging findings were analyzed. Results: Out of 100 patients studied, 87 were males and 17 females with sex ratio 4.9:1. The mean age of all subjects was 54.21 ± 11.23 years. Alcohol was the primary etiology for cirrhosis in 69 (69%) patients while 25 (25%) patients etiology could be identified and labeled as NASH/Cryptogenic. 13% had grade 3-4 hepatic encephalopathy. Liver, renal, coagulation, cerebral, circulatory and respiratory failure were seen in 67%, 32%, 39%, 15%, 39%, 30%, and 13% respectively. Most frequent complication was coagulopathy i.e. INR >2.5, which was found in 36% of patients. The most striking differences were seen in MELD, MELD Na, APACHE II and SOFA scores between no ACLF and ACLF group. Among all four scores, APACHE II had highest sensitivity of 92.7% (p