OBJECTIVE Chronic liver diseases (CLD) may progress to cirrhosis, decompensation and death. An intervening insult may lead to acute decompensation (AD); patients with AD may fulfil criteria for acute-on-chronic liver failure (AD-ACLF). While the outcome of ACLF and priority for liver transplantation have been studied, data on outcome in a non-transplant setting is sparse. We evaluated three international consensus criteria for definition of ACLF to determine the number of patients satisfying these definitions and their accuracy in predicting mortality and compare mortality in a non-transplant setting. METHODS Total 341 consecutive patients with CLD of any etiology were enrolled and followed up. All significant clinical events and changes in laboratory data were noted to classify patients into no AD, AD-ACLF and AD-non-ACLF. RESULTS Total 150 (44%) patients had non-alcoholic fatty liver disease as etiology. As many as 197 (57.8%) patients had AD; of these, 54 (27.4%) met at least one definition of ACLF: 50 (92.6%) fulfilled EASL-CLIF criteria, 31 (57.4%) NACSELD and 22 (40.7%) APASL. The most common precipitating event (59.2%) was infection. Forty-six (13.5%) patients died during the study period - 52% of those with AD-ACLF and 12.6% with AD-non-ACLF (p < 0.00001). The accuracy of EASL-CLIF, NACSELD and APASL definitions in determining mortality was 79.7%, 86.3% and 77.7%, respectively. CONCLUSIONS Total 16% of patients with CLD developed AD-ACLF by any definition; one-half of them died. EASL-CLIF criteria identified maximum number of patients with AD-ACLF, but NACSELD criteria had highest accuracy for predicting mortality in AD-ACLF. These findings may help prioritize patients with ACLF for intensive care in the absence of easy access to liver transplantation.