BACKGROUND: Concordance, which involves prescribing with rather than for patients, should result in less drug wastage (non-use), but is proving hard to put into practice. One possible way of easing elderly people and prescribers toward concordance is to use a medicines organizer (MO). OBJECTIVE: To document medication wastage, using a pharmacy-prepared reusable MO, and explore, using a qualitative approach, use of this information on communication of individuals' drug regimens. METHODS: Sixty-two sheltered housing residents, aged ≥60 years, participated in an exploratory controlled, matched study. The intervention group received medication in the MO, and the control group continued with standard packaging. Community pharmacists recorded details of wasted drugs returned during the 3-month study and, for the intervention group, 6, 9, and 12 months after the study. Medicines management data were collected from participants. Qualitative interviews were conducted with a sample of general practitioners (GPs) and community pharmacists to explore views on the role of the MO. RESULTS: Intervention group wastage was reduced from 18.1% (prestudy) to 1% at 12 months. No data on wastage were collected for the control group after the prestudy assessment. Sixty-one percent more prescription changes, including significant decreases in the number of prescribed drugs and dosages, were reported for the intervention group. GPs and pharmacists reported improvements in communication concerning medication-related dialog. CONCLUSIONS: This small exploratory study has shown that a pharmacy-prepared reusable MO provided visual, objective insights into medication wastage. This resulted in improved communication of drug needs and reduced wastage - the foundation for concordance.