PURPOSE: Vitamin D is known to play an important role in the regulation of the immune system and in the prevention of allergic disease. Herein, we examined the association between vitamin D and allergic rhinitis (AR) in children. METHODS: A total of 72 aeroallergen-proven AR and 57 healthy control subjects who visited Severance Children's Hospital between 2012 and 2014 were evaluated. The mean serum 25-hydroxyvitamin D (25(OH)D) level was measured in all subjects to evaluate their vitamin D status. RESULTS: The mean serum 25(OH)D levels was significantly lower in patients with AR than in controls (19.5±6.4 ng/mL vs. 22.3±5.8 ng/mL, P=0.013). The incidence of AR is higher in the 25(OH)D-insufficient group (15–20 ng/mL) and in the 25(OH)D-deficient group (≤15 ng/mL) compared with the 25(OH)D-sufficient group (>20 ng/mL) (40.3% vs. 84.4% vs. 22.2%, P<0.001). There was no significant difference in the serum 25(OH)D level between subgroups with mild and moderate-to-severe AR symptoms (19.8±6.5 vs. 19.0±6.3, P=0.596). After adjusting for confounding factors, the lower serum vitamin D level groups had increased odds of AR compared with the 25(OH)D-sufficient group (odds ration [95% confidence interval]; 3.67 [1.29–10.38] in the 25(OH)D-insufficient group; P=0.014 and 6.04 [1.49–24.51] in the 25(OH)D-deficient group; P=0.012). CONCLUSION: The serum vitamin D levels were significantly lower in children with AR compared with healthy controls. Therefore, lower serum level of 25(OH)D may be associated with the development of AR.