Although an association of HLA-B*15:02 and PHT-induced SJS/TEN has been noted in Thai and Chinese patients, the number of patients in these studies were too small to draw any definite conclusion. A case-control study was therefore carried out in order to determine relationship between HLA-B*15:02 and SJS/TEN induced by PHT in a Thai population. In this study, 25 patients who have been diagnosed as PHT-induced SJS/TEN and 74 patients who were tolerant to PHT were enrolled as cases and controls. Peripheral blood or buccal swab samples were collected for genomic DNA extraction. The presence of HLA-B*15:02 in these patients were analyzed using a PG1502 DNA detection kit. Among the PHT-induced SJS/TEN patients, 20.00 % carried the HLA-B*15:02 while 14.86 % of the PHT -tolerant controls carried this allele. The prevalence HLA-B*15:02 in the cases and controls was not significantly different among the case and the control groups suggest that HLA-B*15:02 may not be a valid genetic marker for screening Thai patients who at higher risk of PHT-induced SJS/TEN.