Objectives: The role of autoimmune diseases on the risk for acute epiglottitis remains uncertain. This study aimed to delineate the association between epiglottitis and autoimmune diseases using population database. Methods: A population-based retrospective study was conducted to analyze claims data from Taiwan National Health Insurance Research Database collected over January, 2000, to December, 2013. Results: In total, 2339 patients with epiglottitis were matched with 9356 controls without epiglottitis by sex, age, socioeconomic status, and urbanization level. The correlation between autoimmune diseases and epiglottitis was analyzed by multivariate logistic regression. Compared with controls, patients with epiglottitis were much more likely to have preexisting Sjögren syndrome (adjusted odds ratio [aOR]: 2.37; 95% CI: 1.14-4.91; P = .021). In addition, polyautoimmunity was associated with increased risk of epiglottitis (aOR: 2.08; 95% CI: 1.14-3.80; P = .018), particularly in those aged >50 years (aOR: 2.61; 95% CI: 1.21-5.66; P = .015). Conclusions: Among autoimmune diseases, we verify the association between epiglottitis and Sjögren syndrome in Taiwan. Furthermore, we present the novel discovery that patients with epiglottitis have an increased risk of polyautoimmunity, particularly those aged >50 years.