Research on aging and pharmacology in humans has been termed geriatric clinical pharmacology, which is an established subdiscipline within the broad field of clinical pharmacology. This article reviews information relevant to clinical cancer research and the care of older patients with cancer. Accordingly, the current state of knowledge on drug utilization, pharmacokinetics, pharmacodynamics, adverse drug events, drug interactions, polypharmacy, adherence to treatment, and clinical research considerations are reviewed. Although a review of the literature on aging and cancer chemotherapy is not included in this particular presentation, information is very sparse. Thus, there is significant potential for valuable contributions from clinical research through partnerships between geriatric clinical pharmacologists and medical oncologists.