To investigate associations of 2 vitamin D receptor (VDR) gene polymorphisms and acute lower respiratory tract infection (ALRI), we compared 56 young children hospitalized with ALRI and 64 children without a history of ALRI. The FokI ff genotype was associated with an adjusted relative odds of ALRI that was approximately 7 times that of FokI FF. A weaker association with the TaqI polymorphism was also found. These data provide preliminary evidence of associations of VDR polymorphisms with the risk of ALRI (predominantly viral bronchiolitis) in young children, consistent with a potential role of vitamin D in the immune response to respiratory tract infection.