Ethnopharmacologic research has revealed that ethnicity significantly affects drug response. Genetic or cultural factors, or both, may influence a given drug's pharmacokinetics (its absorption, metabolism, distribution, and elimination) and pharmacodynamics (its mechanism of action and effects at the target site), as well as patient adherence and education. In addition, the tremendous variation within each of the broader racial and ethnic categories defined by the U.S. Census Bureau (categories often used by researchers) must be considered. Nurses need to become knowledgeable about drugs that are likely to elicit varied responses in people with different ethnic backgrounds, as well as the potential for adverse effects. The existing ethnopharmacologic research focuses primarily on psychotropic and anti-hypertensive agents, as does this article. Cultural assessment of every patient is vital; thus Leininger's Sunrise Model and Giger and Davidhizar's Transcultural Assessment Models are briefly described as well.