The incidence and potential for serious adverse drug reactions (SADRs) in anesthesia are high due to the narrow therapeutic indices of anesthetic and analgesic drugs and high interindividual variability in drug responses. Genetic factors contribute to a majority of these SADRs. Pharmacogenetics (PG), the study of genetic effects on drug action, is strongly related to the field of anesthesia; historically, succinylcholine apnea and malignant hyperthermia were among the first PG disorders reported. Recent years have strengthened this affiliation with an emerging wide base of knowledge of the effects of genetic variations on the pharmacodynamics and pharmacokinetics of anesthetic drugs. Here, we review the history of anesthetic PG, the important genes influencing enzymes involved in anesthetic drug metabolism, the influence of genotypic expression and the potential ramifications of recent discoveries on the practice of clinical anesthesia. Epigenetics and functional genomics are also discussed. The article also addresses various critical deficits in our current knowledge of PG related to anesthesia that account for the minimal clinical translation of the findings in this area in the present time. The review concludes that in addition to enhanced data generation facilitated by rapidly evolving genetic techniques, robust clinical study designs in a large sample and sound statistical analyses are essential prerequisites for the successful clinical implementation of research findings to individual perioperative care for every patient.