Background: This study aimed to identify the predictors of liver decompensation and mortality in patients with HCC treated with trans arterial radioembolization (TARE). Methods: A retrospective analysis of 140 HCC patients who underwent TARE was conducted. Kaplan-Meier and multivariate Cox regression analyses were performed to identify the key predictors of mortality and liver decompensation, defined as a total bilirubin level greater than 50 mu mol/l or an upgrade in the Child-Pugh class within three months of the first TARE procedure. Results: The cohort comprised 69.3% males with a mean age of 71.3 +/- 11.9 years. Most patients (73.6%) had Child-Pugh class A cirrhosis and 34.3% had BCLC stage B disease. Liver decompensation was recorded in 55 patients (39.2%) within three months of the first TARE procedure. A total of 80 patients (57.1%) died during the follow-up period. The median survival was significantly longer in those without liver decompensation (3.2 vs. 0.7 years, P < 0.001). Multivariate analysis revealed that male gender (adjusted odds ratio [aOR] 5.889, P = 0.009), cirrhosis (aOR 6.82, P = 0.047), and baseline international normalized ratio (INR) (aOR 316.664, P = 0.013) were independent predictors of liver decompensation. Cox regression analysis revealed several significant predictors of increased mortality including ascites (HR 2.012, 95% CI, 1.122-3.61; P = 0.019), portal vein invasion (HR 1.695, 95% CI, 1.057-2.718; P = 0.029), and diabetes mellitus (HR 1.823, 95% CI, 1.017-3.265; P = 0.044). Conversely, non-multifocal HCC (HR 0.593, 95% CI, 0.369-0.955; P = 0.031), treatment of the liver lobe other than the right lobe (HR, 0.482; 95% CI 0.236-0.986, P = 0.046), and age >= 60 years (HR 0.288, 95% CI, 0.139-0.597; P = 0.001) were associated with a reduced risk of mortality. Conclusion: This study identified the key predictors of liver decompensation and mortality in patients with HCC undergoing TARE, potentially improving patient selection and management strategies.