ABSTRACT: Recent evidence links rosacea to systemic disease, but there are not enough methodologic studies addressing this association in Asians. Our aim was to identify rosacea comorbidities in Koreans and establish a reference database. A multi-center, case-control study was performed where a total of 12,936 rosacea patients and 12,936 age- and sex-matched control subjects were identified from 2007 to 2018. Logistic regression was performed to find significant association between rosacea and Sjögren syndrome (odds ratio [OR] 2.05; 95% confidence interval, 1.40-3.00), systemic sclerosis (OR 6.56; 95% CI, 1.50-28.7), rheumatoid arthritis (OR 1.72; 95% CI, 1.50-1.98), ankylosing spondylitis (OR 2.32; 95% CI, 1.42-3.84), autoimmune thyroiditis (OR 1.96; 95% CI, 1.40-2.73), alopecia areata (OR 1.77; 95% CI, 1.27-2.45), vitiligo (OR 1.90; 95% CI, 1.30-2.77), lung cancer (OR 1.54; 95% CI, 1.06-2.21), hepatobiliary cancer (OR 1.38; 95% CI, 1.06-1.77), alcohol abuse (OR 1.59; 95% CI, 1.05-2.39), diabetes mellitus (OR 1.11; 95% 1.02-1.19), obesity (OR 1.72; 95% CI, 1.22-2.41), allergic rhinitis (OR 1.65; 95% CI, 1.54-1.76), allergic conjunctivitis (OR 1.57; 95% CI, 1.27-1.94), chronic rhinosinusitis (OR 1.28; 95% CI, 1.14-1.42), herpes infection (OR 1.69; 95% CI, 1.53-1.86), and human papillomavirus infection (OR 2.50; 95% CI, 2.06-3.02). Higher odds for Sjogren syndrome, systemic sclerosis, ankylosing spondylitis, thyroiditis, vitiligo, hepatobiliary cancer, and obesity was exclusive in female subjects with rosacea, whereas increased prevalence of alopecia areata and alcohol abuse was confined to men. Only those who were 50 years and older exhibited higher odds for vitiligo, lung cancer, and gastroesophageal reflux disease while individuals younger than 50 were exclusively associated with hepatobiliary cancer, allergic conjunctivitis, and irritable bowel syndrome. Our study suggests that Koreans with rosacea are more likely to experience systemic comorbidity. Clinicians should acknowledge these interrelations and employ comprehensive care with an individual-based approach.