The use of medicines in care homes could be improved, and as a result, the health of residents would be better. Pharmacist prescribers (i.e., pharmacists specifically trained and qualified to prescribe) have been shown to provide safe, quality care in other patient groups. We proposed to test if making “pharmacist prescribers” part of the care home team, working alongside general practitioners, could improve the use of medicines and the care of residents. These pharmacist prescribers authorized monthly prescriptions while carefully monitoring how each resident responded. We believed that such a change to the management of medicines in care homes was likely to be a good use of NHS money. This paper describes a series of developmental studies that were undertaken as part of a program of work which followed the Medical Research Council Framework for developing and evaluating a complex intervention. The rationale for each study is described and for the final of these feasibility studies, when all components were tested together, we consider what went well, some of the challenges we encountered, and how they informed our decision to progress to a definitive randomized controlled trial.