Abstract Background: Toll-like receptor 2 (TLR2) is essential for the immune response to tuberculosis (TB). The goal of the present study was to investigate whether the guanine-thymine (GT) repeat microsatellite polymorphism in intron 2 of the TLR2 gene might be correlated with susceptibility to TB in Han Chinese. Methods: The number of (GT)n repeats was determined by gene scanning from 244 patients with TB and 233 control subjects. The expression of TLR2 on CD14+ peripheral blood mononuclear cells was determined using flow cytometry. Results: No association in allelic polymorphism between control subjects and patients with TB was found. However, the S/M genotype of the microsatellite polymorphism was more frequent in TB patients than in healthy controls (p=0.01). The S/L genotype was more popular in controls than in patients with TB (p=0.007). TLR2 expression was higher in subjects with the S/L genotype than in those with the S/M genotype (p<0.05). Conclusions: Our data suggest that the S/M genotype of the microsatellite (GT)n polymorphisms in intron 2 of the TLR2 gene may increase susceptibility to TB in Chinese, and the S/L genotype may act as a negative risk factor. Clin Chem Lab Med 2010;48:785–9.