The family of T-cell immunoglobulin domain and mucin domain (TIM) proteins is identified to be expressed on T cells. A member of the TIM family, TIM-3 is selectively expressed on the surface of differentiated T helper 1 (Th1) cells. TIM-3 might have an important role in the induction of autoimmune diseases by regulating macrophage activation and interacts with the TIM-3 ligand to regulate Th1 responses. In the present study, we analyzed the association of the genotype and allele frequencies between asthma or allergic rhinitis patients and nonatopic controls using large samples size at -1516G > T, -574T > G, and 4259G > T polymorphic sites of the Tim-3 gene. The genotype and allele frequencies of -574T > G polymorphism in asthma patients (p = 0.042 and p = 0.017, respectively) as well as allergic rhinitis patients (p = 0.008 and p = 0.003, respectively) were significantly different from those of nonatopic controls. Furthermore, the allele frequency of 4259G > T polymorphism in allergic rhinitis patients (p = 0.029) was also significantly different. Our results strongly suggest that the -574T > G polymorphism of Tim-3 might be associated with the susceptibility of atopic diseases such as asthma and allergic rhinitis.