Genetic studies on drug-induced liver injury (DILI) have proved challenging, both because of their rarity and their difficulty in replicating observed effects. However, significant progress has now been achieved by both candidate-gene and genome-wide association studies. These two approaches are considered in detail, together with examples of DILI due to specific drugs where consistent associations have been reported. Particular consideration is given to associations between antituberculosis drug-related liver injury and the "slow acetylator" genotype for N-acetyltransferase 2, amoxicillin/clavulanate-related liver injury, and the human leukocyte antigen (HLA) class II DRB1*1501 allele and flucloxacillin-related injury and the HLA class I B*5701 allele. Although these associations are drug-specific, the possibility that additional, more general susceptibility genes for DILI exist requires further investigation, ideally by genome-wide association studies involving international collaboration. The possibility of interethnic variation in susceptibility to DILI also requires further study.