Background: Obesity, a prominent issue in global health, is known to increase the risk factors associated with a variety of cancers, including hepatocellular carcinoma (HCC), the most common type of primary liver cancer. While existing research affirms the heightened risk of developing HCC in individuals with obesity, there remains a significant gap in understanding the specific influences of obesity on the outcomes of patients admitted with primary HCC diagnosis during their index hospital admission. This study explores the mortality rate, length of stay (LOS), and healthcare utilization in HCC patients with and without obesity. Methods: Nationwide Inpatient Sample (NIS) was queried to determine adult hospitalized patients with a primary diagnosis of HCC using ICD-10 codes. The primary outcome was defined as the effect of obesity on inpatient mortality in those patients. Secondary outcomes included LOS, total hospital charge, health care utilization, ICU admission. We evaluated the baseline characteristics using the t-test and chi-square test. Multivariable logistic regression analysis was performed to assess the association of HCC with obesity and inpatient mortality adjusted by age, gender, race, Charlson index, insurance, and household income. Results: A total of 62,050 HCC patients were identified, and 10.9% of these patients had obesity. HCC patients with obesity were younger (64.7 vs. 65 years, p=0.220), more likely to be female (32.2% vs. 24%, p < 0.001), White (59.8% vs. 50.2% p < 0.001), and more likely to have no insurance (28.8% vs. 23.3%, p < 0.001) compared to HCC patients without obesity. HCC with obesity had higher mean Charlson Comorbidity index 5.9 vs. 5.5, p < 0.001). The overall inpatient mortality rate was 8.2% for all patients who are admitted for HCC; lower in HCC with obesity (5.6%) vs HCC without obesity (8.5%) (p < 0.001). Charlson index, Male gender, African–American race, Hospital teaching status, insurance status found to be associated with inpatient mortality among HCC hospitalizations. HCC with obesity had a lower odds ratio with decreased all-cause mortality of 25% compared to HCC without obesity (aOR 0.75, 95% CI 0.58-0.96, p = 0.023). In addition, HCC with obesity was associated with increased LOS mean 6.3 vs. 5.7 days (adjusted difference: 0.6 p < 0.001), and total hospital charges (mean $112,687 vs $88,481, adjusted difference: $21122 p < 0.0001). Also; ICU transfer rate and AKI development were found more in obese cohort and this different was statistically significant. Conclusions: Our study revealed that HCC patients with obesity had a lower inpatient mortality rate compared to those without obesity, despite longer hospital stays and higher costs. These findings hint at a complex interplay between obesity and HCC outcomes, necessitating further in-depth research.