BACKGROUND: Innate immunity receptors play a critical role in host defense. In addition, the expression of Toll-like receptors (TLRs) has been connected to allergy and asthma. AIMS: : To evaluate the association between the TLR3 L412F polymorphism and viral findings, clinical characteristics and subsequent wheezing in young infants with bronchiolitis. METHODS: In all, 129 full-term infants hospitalized for bronchiolitis at age <6 months have been followed-up until the mean age of 1.5 years. Genotyping of the TLR3 L412F gene mutation was made by pyrosequencing. RESULTS: TLR3 L412F gene polymorphism including the minor allele T was overrepresented (52%) in infants hospitalized with bronchiolitis. The presence of the major allele C as homozygous was associated with repeated postbronchiolitis wheezing (7.06, 95% confidence interval 2.30-21.66). CONCLUSION: Preliminary evidence was found that TLR3 L412F gene polymorphism may be associated with bronchiolitis leading to hospitalization and postbronchiolitis wheezing.