It has long been recognized that drug metabolism and drug toxicity may vary greatly between individuals, affecting both efficacy and toxicity. Pharmacogenetics could benefit HIV therapeutics because of the high prevalence of drug-related adverse events and the long term nature and complexity of combination therapy. In recent years a number of associations between human genetic variants and predisposition to drug toxicity and risk of virologic failure have been described. This review summarizes the existing literature on pharmacogenetic determinants of antiretroviral drug exposure, toxicity, and activity. Studies across the world have consistently demonstrated that HLA-B*5701 predicts the likelihood of hypersensitivity reactions to abacavir. As a consequence, pharmacogenetic screening for HLA-B*5701 has entered routine clinical practice and is recommended in most guidelines before starting an abacavir containing regimen. Moreover, prospective clinical trials and cohort studies have identified a number of associations between human genetic variants, drug metabolism and toxicity. These include nevirapine hypersensitivity and hepatotoxicity, efavirenz plasma levels and central nervous system side effects, indinavir- and atazanavir-associated hyperbilirubinemia, antiretroviral drug-associated peripheral neuropathy, lipodystrophy and hyperlipidaemia, NRTI-related pancreatitis, and tenofovir-associated renal proximal tubulopathy. Thus, pharmacogenetics is expected to play an important role in HIV treatment in the near future. The aim of the present paper is to provide HIV clinicians with a comprehensive review of recent achievements and future prospects for HIV pharmacogenetics.