Background: Sorafenib (SOR) is the only FDA-approved systemic therapy for advanced hepatocellular carcinoma (HCC). In clinical practice, there are limited efficacy data related to dose modifications, which are often required. Given the high prevalence of HCC in South Texas, we assessed the efficacy and safety of SOR therapy in relation to dose and Child Pugh score (CP). Methods: Retrospective analysis of HCC patients (pts) receiving SOR from 2008-2013. Median progression-free survival (mPFS) and median overall survival (mOS) were estimated from Kaplan-Meier curves and groups were statistically compared with the log rank test. The magnitude of association between dichotomous factors and survival was estimated with the hazard ratio (HR). A proportional hazards regression model was used to assess the significance of SOR (low, high) by CP (A, B) interaction. Results: 107 pts were included. Median age 57 (41-93). Males 83%. Hispanic 72%, White 24%. ECOG PS 0–1 93%. Causes of cirrhosis: Hepatitis C 67%, Hepatitis B 5%, EtOH 60%. Portal vein thrombosis 33%, extrahepatic disease 39%. CP (available for 106 pts): A 57%, B 43%. mOS was 10.2 months (mo) (95% CI: 7.8-13.5); mPFS was 5.2 mo (95% Cl: 3.8-7.2). In subgroup analysis, mOS for 800 mg/day was 12.8 mo vs 6.6 mo for 400 mg/day (HR 0.59, p=0.04). mPFS for 800 mg/day was 5.9 mo vs 3.5 mo for 400 mg/day (HR 0.66, p=0.07). In CP A pts, higher SOR dose did not improve survival; however, in CP B pts, there were statistically significant improvements in mPFS and mOS (Table). The effect of dosage varied significantly with CP category (A, B) for both OS (p=0.002) and PFS (p=0.03). Conclusions: Historically, CP B advanced HCC pts have worse survival and tolerability to higher doses of SOR when compared to CP A. Our study suggests CP B pts should be considered for SOR 800 mg/day to improve survival with optimal management of toxicity but warrants further prospective studies.