Purpose of reviewDrug hypersensitivity reactions constitute an unpredictable, serious problem for health care systems as they interfere with drug treatment, limit therapeutic options, and may be life-threatening. In addition to specific patient factors, they are also influenced by a genetic component. Indeed, a considerable body of knowledge supports the participation of genetic variants in their underlying mechanisms.Recent findingsLatest research on this topic confirms the involvement of specific HLA alleles in non-immediate reactions. Two well-known examples are the HLA-B*58:01 allele in severe allopurinol-triggered reactions, and the HLA-B*15:02 allele in carbamazepine-induced Stevens-Johnson syndrome/toxic epidermal necrolysis. However, there is a lack of reliable genetic markers for immediate reactions and for hypersensitivity to NSAIDs.SummaryWe summarize available information on the genetics of drug hypersensitivity reactions, highlighting regulatory agencies recommendations when available. We include some comments about new technological tools that should be implemented in the study of these reactions.