Background: Stereotactic body radiation therapy (SBRT) may benefit patients with hepatocellular carcinoma (HCC) who are not candidates for other liver-directed therapies due to poor liver function (plf). However, optimal patient selection, safety, and efficacy of SBRT in plf-HCC patients are not known. We studied dosimetric, baseline liver function, and radiographic features at the time of treatment that may help identify HCC patients with liver dysfunction who would benefit most from SBRT. Methods: Medical records of plf-HCC patients with cirrhosis treated with SBRT at a single institution between 2013-2016 were reviewed. Prescription doses were tailored to liver function based on INR and total bilirubin (tBili) and uninvolved liver volume. Time to local progression was evaluated using cumulative incidence analysis (Gray’s test) and competing risks regression analysis. Local progression was defined using RECIST criteria. Overall survival was estimated using the Kaplan-Meier method and Cox proportional hazards model. Results: 26 plf-HCC patients with median baseline MELD 11 (range 1-35), tBili 1.6 (0.5-6.5), INR 1.2 (1.0-9.0), tumor size of 4.1 cm (1.7-8.5 cm), and liver volume 1251 cc (596-2322 cc) were treated with SBRT. 54% received SBRT for retreatment of the same tumor. Patients were heavily pretreated with 50%, 19%, and 8% previously receiving TACE, ethanol ablation, and RFA, respectively. With a median prescription of 30 Gy (8-50 Gy) in 5 fractions (2-5), the median liver dose was 8 Gy (3-14 Gy). Median increase in MELD 90 days post-SBRT was 1.1 (0-19), with 35% experiencing no increase and 25% increasing >2.5. Local control (LC) was 55% at 6 months with one patient bridged to liver transplant. LC was not associated with improved survival (p = 0.39) and median overall survival (MS) was 8.6 months (0.9-31.7 mo). However, longer MS was seen for patients without ascites (MS=16.5 vs. 4.1 mo, p = 0.005), tBili < 2 (MS=16.5 vs. 5.2 mo, p = 0.015) and MS was not reached in patients treated to > 30 Gy (p = 0.04) or with MELD < 11 (p = 0.02). Conclusions: In this cohort of HCC patients with poor liver function, the absence of ascites, tbili < 2, and lower MELD scores were associated with improved survival following SBRT.