HLA-B frequencies in 54 unrelated nasopharyngeal carcinoma (NPC) patients and 49 healthy random controls in Thailand were investigated by direct DNA sequencing. Similar to previous reports in Chinese NPC patients, HLA-B*4601 was observed at a greater frequency in patients (21/54 (40%)) compared to controls (7/49 (14%). An increase in HLA-B*51012 was also demonstrated. B*51012 was present in 6/54 (11%) NPC patients but was not observed (0%) in controls. B*44032 was associated with a decreased risk. Five out of 54 (9%) NPC patients had B*44032 compared to 14/49 (29%) in the control group.