ABSTRACT: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are acute-onset mucocutaneous diseases induced by infectious agents and/or inciting drugs. We have reported that the main causative drugs for SJS/TEN with severe ocular complications (SOC) were cold medicines, including multi-ingredient cold medications and nonsteroidal anti-inflammatory drugs (NSAIDs). Moreover, we also reported that acetaminophen is the most frequent causative drug in various cold medicines. In this study, we focused on acetaminophen-related SJS/TEN with SOC and analyzed HLA-class II (HLA-DRB1, DQB1) in addition to HLA-class I (HLA-A, B, C). We studied the histocompatibility antigen genes HLA-DRB1 and DQB1 in addition to HLA-A, B, and C in 80 Japanese patients with acetaminophen-related SJS/TEN with SOC. We performed polymerase chain reaction amplification followed by hybridization with sequence-specific oligonucleotide probes (PCR-SSO) using commercial bead-based typing kits. We also used genotyped data from 113 healthy volunteers for HLA-DRB1 and DQB1, and 639 healthy volunteers for HLA-A, B, and C. HLA-DRB1*08:03 and DRB1*12:02 were associated with acetaminophen-related SJS/TEN with SOC, although the results ceased to be significant when we corrected the p-value for the number of alleles detected. HLA-A*02:06 was strongly associated with acetaminophen-related SJS/TEN with SOC (carrier frequency: p = 4.7 × 10-12, Pc = 6.6 × 10-11, OR = 6.0; gene frequency: p = 8.0 × 10-13, Pc = 1.1 × 10-11, OR = 4.9). HLA-B*13:01 (carrier frequency: p = 2.0 × 10-3, Pc = 0.042, OR = 4.1; gene frequency: p = 2.2 × 10-3, Pc = 0.047, OR = 3.9), HLA-B*44:03 (carrier frequency: p = 2.1 × 10-3, Pc = 0.045, OR = 2.4) and HLA-C*14:03 (carrier frequency: p = 3.4 × 10-3, Pc = 0.045, OR = 2.3) were also significantly associated, while HLA-A*24:02 was inversely associated (gene frequency: p = 6.3 × 10-4, Pc = 8.8 × 10-3, OR = 0.5). Acetaminophen-related SJS/TEN with SOC was not associated with HLA-class II (HLA-DRB1, DQB1). However, for acetaminophen-related SJS/TEN with SOC, we found an association with HLA-B*13:01 and HLA- C*14:03 in addition to HLA-A*02:06 and HLA-B*44:03, which have been described previously.