Background: Primary liver cancer is the third most frequent cause of cancer-related death worldwide, with hepatocellular carcinoma (HCC) composing 75% of cases. Recent preclinical models suggest that immunotherapy targeting programmed cell death protein 1 (PD-1) leads to CD8+ T-cell activation but not tumor regression in nonalcoholic fatty liver disease (NAFLD) induced HCC. However, additional studies are required to understand the response of NAFLD-associated HCC patients to PD-1 and programmed death-ligand 1 (PD-L1) therapies. Methods: Our team conducted a retrospective, single center study to determine the best responses to anti-PD-1/PD-L1 containing regimens in patients with HCC and underlying NAFLD cirrhosis. There were 2 groups included in this study: patients with HCC associated with NAFLD cirrhosis and those who had HCC without NAFLD cirrhosis. All patients included in this study received either an anti-PD-1/PD-L1 targeted agent as monotherapy or combined with other systemic treatment. Radiologic evaluations were conducted between February 2018 and January 2022. Results: There were 81 patients were included in this study: 15 in the NAFLD cirrhosis HCC group and 66 in the HCC group without NAFLD cirrhosis. When determining the best responses to anti-PD-1/PD-L1 therapies, 6 patients (40%) with HCC and NAFLD cirrhosis had disease progression as their best responses versus 7 patients (10.6%) who had HCC without NAFLD cirrhosis (risk ratio 3.8, p = 0.012). Furthermore, in the HCC group without NAFLD cirrhosis, 59 patients (89.4%) experienced disease control (defined as stable disease, partial response, or complete response) from anti-PD-1/PD-L1 containing regimens compared to 9 patients (60%) in the NAFLD cirrhosis-related HCC group (risk ratio 1.5, p = 0.012). No significant differences were found in gender, patient age, or treatment regimens received between the two groups. See the table below for details on immunotherapy regimens and treatment responses. Conclusions: In this study, HCC patients with NAFLD cirrhosis experienced significantly higher rates of disease progression as the best response to anti-PD-1/PD-L1 therapies compared to HCC patients without NAFLD cirrhosis. As the use of immunotherapy in the HCC population continues to expand, additional prospective studies are necessary to clarify the impact of underlying liver disease on treatment response.