Tuberculosis is an important infectious disease in Thailand. Susceptibility to tuberculosis is influenced not only by the environment but also by host genetic factors. In this study, we investigated HLA alleles in 82 patients with tuberculosis from Bangkok and in 160 normal controls. HLA-DRB1, DQA1 and DQB1 genotyping was performed by the PCR-SSO method. The frequency of HLA-DQB1*0502 was increased in tuberculosis patients compared to the normal controls (P = 0.01, OR = 2.06). In contrast, the frequencies of DQA1*0601 and DQB1*0301 were decreased in tuberculosis patients compared to the controls (P = 0.02 and P = 0.01, respectively). Our results suggest that HLA-DQB1*0502 may be involved in the development of pulmonary tuberculosis, whereas HLA-DQA1*0601 and DQB1*0301 may be associated with protection against tuberculosis.