We report on the first polypharmacy adherence monitoring over 371 days, integrated into a pharmaceutical care service (counselling, electronic multidrug punch cards, feedback on recent electronic records) for a 65-year-old man with diabetes after hospital discharge. The initial daily regimen of four times per day with 15 pills daily changed after 79 days into a daily regimen of two times per day with 9 pills daily for the next 292 days. The patient removed all medication from the multidrug punch cards (taking adherence 100%) and had 96.9% correct dosing intervals (timing adherence). The 57 evening doses showed the least variation in intake times at 17 h 45 min±8 min. Over the observation year, the patient was clinically stable. He was very satisfied with the multidrug punch card and the feedback on electronic records. In conclusion, long-term monitoring of polypharmacy was associated with the benefit of successful disease management.