The market for molecular diagnostic tests is predicted to grow at extraordinary rates over the next 10 years, fueled by pharmacogenetics and the elusive dream of personalized medicine. The challenge is managing the expectations of the medical community and the public at large that have already been set by speculation, promises, and the repeated exposure to headlines about genetic discoveries. Personalized medicine is a paradigm that exists more in conceptual terms than in reality, with only a few marketed drug-test companion products and not very many actual clinical practices set up to personalize medicine in the way that supporters have intended. Nevertheless, the reality of personalized medicine has become more imminent because of the increased awareness of the shortcomings in the delivery of drugs with adequate benefit/risk to patients, a better molecular understanding of how to optimize drug selection and dosing, and an increased demand for integrating more clinically relevant genetic information into the drug development process to improve both innovation and productivity. This paper focuses on personalized medicine by (1) looking at some converging changes taking place in the health-care landscape that are creating a scientific and social infrastructure to enable personalized medicine, (2) considering challenges that need to be addressed with regard to clinical evidence standards for validating genotype-phenotype associations, and (3) considering how clinical pharmacology can help construct a rational personalized medicine framework. As therapeutic experts, clinical pharmacologists can work to assure that "good therapeutics follows good diagnostics". They are well equipped to provide timely genetic education to others and to interpret genetic data so that actionable decisions, especially about drug dosing in individual patients, can be implemented in clinical practice.