INTRODUCTION: A condition of high short-term mortality in the cirrhotic patient is Acute-on-Chronic Liver Failure (ACLF), characterized by organ failure (s) and usually preceded by acute decompensation (AD). OBJECTIVE: To determine the frequency, clinical profile, and mortality in cirrhotic patients hospitalized with ACLF. MATERIALS AND METHODS: This is an observational analytical study conducted from July 2016 to June 2017. We established the ACLF condition through the criteria of the CANONIC study. RESULTS: The study population was 118 patients, of whom 34 (28.8%) presented ACLF, 14 (41%) were Grade 1, 16 (47%) Grade 2 and 4 (11.9%) Grade 3. The average age was 61.5 years old, alcoholism being the most frequent etiology with 18 patients (53%) and mostly without episodes of AD (64.7%). The most frequent precipitating factors were: Digestive hemorrhage (41%) and infections (29.4%). The groups with and without ACLF were statistically significant in the Child-Turcot-Pugh score (CTP) (11.4 ± 1.8 vs. 8.69 ± 2.04; p < 0.0001 ). MELD score (26.4 ± 8.1 vs. 14.4 ± 4.6; p < 0.0001), leukocytes (11,809.7 +/- 6,906.3 per mm3 vs. 8,434.01 ± 5,434.9 per mm3; p: 0.006) and 28-day mortality (76.5% vs. 21.4%, p < 0.0001), with a relative risk (RR) of 3.5. CONCLUSIONS: The frecuency of ACLF was 28.8%, similar to that of the CANONIC study (30.9%). The digestive hemorrhage being the main precipitating factor. The CTP, MELD and leukocyte scores were highest in this group. Mortality in patients with ACLF was 3.5 times more frequent than in patients without ACLF.