Purpose of review Epigenetics dictate how the genetic blueprint is ultimately expressed and, therefore, is fundamental to our understanding of disease etiology and cellular responses and consequences to exposure of stimuli, such as anesthetics and perioperative stress. The goal of this review is to provide a concise overview of the fundamental concepts in epigenetics and discuss how epigenetics may be incorporated into research studies in anesthesiology. Recent findings Chemical modifications of DNA and core histone proteins are epigenetic marks that constitute the functional genome and are key to generating diverse cellular phenotypes from the same genotype. These modifications and the cellular machineries that regulate them are essential for maintaining tissue-specific and timing-specific expression profiles for normal functioning and can be altered in disease contexts, thus providing the molecular basis for the abnormalities. Similar to determining cellular identity within a person, epigenetic differences between individuals, including monozygotic twins, can account for disparate phenotypes in the absence of genetic variation in the genes of interest. Furthermore, epigenetic modifications are dynamic but heritable and, thus, are fitting for reinforcing adaptive phenotypes in response to external stimuli. Summary Epigenetic mechanisms underlie many human pathological conditions and impact clinical management in a variety of contexts. Although epigenetic research related to anesthesiology is sparse at the present, the full understanding of the mechanism of action of analgesics, interindividual variations in responses to anesthetics and consequences of exposure to anesthetic drugs will likely require the evaluation and integration of epigenetic information into current research paradigms.