OBJECTIVES: Non-alcoholic steatohepatitis (NASH) have been recognised as a significant form of chronic liver disease and a common cause of cirrhosis and hepatocellular carcinoma, resulting in a large healthcare financial burden. Currently, there is no information regarding the economic burden of NASH in low- and middle-income countries (LMICs). The aim of this study was to estimate the economic burden of NASH in Thailand as a lesson learned for LMICs. METHODS: To estimate the healthcare costs and prevalence of NASH with significant fibrosis (fibrosis stage≥2) among Thai general population, an eleven-state lifetime horizon Markov model with 1-year cycle length was performed. The model comprised Thai population aged 18 years and older. Cohort size was based on Thailand Official Statistic Registration Systems. The incidence of NASH, transitional probabilities, and costs-of-illness were based on previously published literatures, including systematic reviews and meta-analyses. The age-specific prevalence of NASH was based on Thai NASH registry data. Costs were expressed in 2019 US Dollar ($). As we undertook analysis in payer perspective, only direct medical costs were included. All future costs were discounted at annual rate of 3%. A series of sensitivity analysis was performed. RESULTS: The estimated total number of patients with significant NASH was 2.9 million cases in 2019 based on NASH prevalence of 5.74%. The total lifetime cost of significant NASH was $15.2 billion ($5,147 per case), which was approximately 3% of 2019 GDP of Thailand. The probabilistic sensitivity analysis showed that the lifetime costs of significant NASH varied from $11.4 billion to $18.2 billion. CONCLUSIONS: The economic burden associated with NASH is substantial in Thailand. This prompts clinicians and policy makers to consider strategies for NASH prevention and management.