The interleukin 4 receptor (IL4R) polymorphism Q576R (rs 180275) has been well known to be associated with atopy and other inflammatory diseases. A single nucleotide polymorphism (SNP) A > G transition potentiates the binding specificity of the adjacent tyrosine residue. In this study we investigated the possible relationship between sudden deafness (SD) and IL4R polymorphism Q576R in 97 Korean SD patients and 613 controls using pyrosequencing method. The odds ratio (OR) for SD associated with the G vs. A allele was 2.58 [P < 0.0001, 95% confidence interval (CI) = 1.84-3.60]. We then sub-grouped SD into Tinnitus positive (+) and Tinnitus negative (-). G allele in Tinnitus (+) is significantly associated with the development of Tinnitus (+) [X(2) = 32.02, P < 0.0001, OR (95% CI) = 2.74 (1.91-3.93)] but not with Tinnitus (-). Taken together these results suggest that G allele could be a risk factor for SD.