There is substantial variability in patients’ response to medications. The healthcare system is in the midst of a transformation to a targeted precision health approach in which disease treatment and prevention take into account individual genetic variability. This change is informed by studies, which show that genetic variations alter the structure and function of proteins such as drug transporters, drug-metabolizing enzymes, and receptors. Tailoring medication administration based on genetic makeup can minimize adverse effects and maximize efficacy. As a result, many healthcare centers have begun incorporating genomic information into healthcare decision making. Unfortunately, many anesthesia providers may be unfamiliar with the genetics concepts and principles underlying variability in patients’ response to medication. This article reviews genetic diversity in humans and the various ways in which this genetic variability may influence pharmacokinetics and pharmacodynamics of drugs. This knowledge will ensure that anesthesia providers can effectively tailor anesthesia care and postoperative pain management to improve outcomes.