BACKGROUND: There is still little knowledge about the association of liver fibrosis with the clinical outcomes of COVID-19 patients with non-alcoholic fatty liver disease (NAFLD). The aim of the study was to determine the association of NAFLD fibrosis score (NFS)-determined liver fibrosis with clinical outcomes of COVID-19 patients with NAFLD. METHODS: The NAFLD was diagnosed by the Hepatic Steatosis Index (HSI) in the absence of other causes of chronic liver diseases. NFS was used to evaluate the severity of liver fibrosis. RESULTS: A total of 86 COVID-19 patients with NAFLD were included. The median age was 43.5 years, and 58.1% of patients were male. Thirty-eight (44.2%) patients had advanced liver fibrosis according to the NFS. Multivariate analysis indicated that concurrent diabetes (odds ratio [OR] 8.264, 95% confidence interval [CI] 1.202-56.830, p = 0.032) and advanced liver fibrosis (OR 11.057, 95% CI 1.193-102.439, p = 0.034) were independent risk factors of severe illness in COVID-19 patients with NAFLD. CONCLUSION: NAFLD patients with NFS-determined advanced liver fibrosis are at higher risk of severe COVID-19.