Background: Coronavirus disease 2019 (COVID-19) is serious infectious disease that may require intensive care unit (ICU) admission and exposes patients to adverse events. Aim: To identify factors predicting the occurrence adverse events in COVID-19 critically ill patients. Methods: A retrospective cohort study conducted between September 19th, 2020, to December 31st, 2021, in a medical ICU including all admitted COVID-19 patients. Baseline and clinical characteristics and outcomes were recorded. Univariate and multivariate analysis were used to identify predictors of adverse events. Results: Were admitted 172 patients. Mean age was 51.46±14.3 years, median Charlson comorbidity index (CCI) and SAPSII score were respectively 1[0-2] and 24[18-32]. The most common comorbidities were obesity 60(34.9%) and diabetes 49(28.5%). Nine (5.2%) patients were treated by invasive mechanical ventilation (IMV) at admission. Vasopressors was used in 64(37.2%) patients. The morality rate was 40.7%. Sixty-six (38.4%) patients experienced 134 adverse events: nosocomial infection, 58(33.7%); acute renal failure, 51(29.7%); bedsores, 13(29.7%); bleeding complications, 9(45.2%) and barotrauma, 3(2.1%). Predictors of adverse events in univariate analysis: age (p=0.000); CCI (p=0.000); SOFA (p=0.000); IMV (p=0.000); vasopressors use (p=0.000) and ICU length of stay (LOS) (p=0.000). In multivariate analysis, CCI (OR, 1.43; 95%CI, [1.03-1.97]; p=0.031), IMV (OR, 15.8; 95%CI, [6.19-40.45]; p=0.000) and ICU LOS (OR, 1.11; 95%CI, [1.02-1.21]; p=0.01) were independent factors. Conclusion: CCI, IMV and LOS were predictors of adverse events? occurrence in ICU COVID-19 patients. Clinicians should be aware of them, and preventive measures must be implemented.