The variations in response to pharmacotherapy can in part be explained by genetic factors. Pharmacogenetics, a term coined in the 1950's, describes these relationships. Great technological advances in molecular biology and computational sciences, crowned by the sequencing of the human genome, have brought forth the current interest in pharmacogenetics. Continued technological developments may lead to the understanding of the molecular mechanisms behind complex diseases like cardiovascular disease, and holds the promise of individualized pharmacotherapy. The article gives a background to the field, with emphasis on antihypertensive therapy, and prospects for the future.