The study investigates the association between HLA-B alleles and carbamazepine (CBZ)-induced Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) in the Javanese and Sundanese populations of Indonesia. The findings reveal that the HLA-B*15:02 allele is significantly more prevalent in patients with CBZ-induced SJS/TEN compared to tolerant controls, with the presence of the HLA-B75 serotype further strengthening the association. This research highlights the importance of HLA screening in predicting the risk of severe adverse drug reactions to CBZ in these ethnic groups.