Background <p>Mental disorders are a major cause of the economic burden of disease worldwide, and in China, mental disorders consume a large amount of health care resources and impose a heavy economic burden on society, families, and individuals. The aim of this study was to analyze the medical costs associated with mental disorders in Jilin Province, China, and the related factors affecting medical costs.</p> Methods <p>Patients were selected by multistage stratified cluster random sampling. All patient records from 446 health care institutions in Jilin Province from 2020 to 2022 were analyzed to characterize their medical costs. T tests, ANOVA and hierarchical regression were used to explore the related factors influencing medical costs.</p> Results <p>The average medical cost in Jilin Province from 2020 to 2022 was 225.9&#xa0;million dollars. Drugs accounted for the largest proportion of medical costs. Hierarchical regression analysis revealed that days of hospitalization, the medical payment method, and the institutional level were positively correlated with medical costs; gender, age, the disease type, comorbidities, the institutional type, the nature of institution, and treatment services were negatively correlated with medical costs(<i>p</i> &lt; 0.05).</p> Conclusions <p>Mental disorders often present a substantial economic burden. Efforts must be made to help policy-makers develop effective strategies to reduce the medical burden of mental disorders.</p>