A nationwide survey was conducted to verify relations between the workload of home-visiting service by community pharmacists and outcomes. Data were collected on 5447 patients from 1890 pharmacies. Most (61.9%) pharmacists visited patients' homes twice monthly, spending there a net average of 20.6 work minutes. At the time of the survey, 29.8% of the patients had improvement of adherence compared with at start of home visits; 65.5% had no change, and 1.4% had gotten worse. Similarly, 41.6% had decreased unused medications, 54.4% had no change, and 2.3% had increased. Home-visiting pharmacists found adverse drug events (ADEs) caused by drug administration in 14.4% of their patients. They dealt with 44.2% of these cases by discontinuing administration of the responsible drug, 24.5% by reducing the dosage, and 18.3% by changing drugs, with a total of 88.1% having been improved. Prescription changes intended to correct problems occurred in 37.1% of the patients. In patients whom the pharmacists visited more often, a higher percent had ADEs, had their prescription changed to correct problems, and had improved adherence and unused medications. The average actual work time was longer in patients whose outcomes improved than in those whose outcomes did not. A higher involvement in homecare by pharmacists was found to improve outcomes of drug treatment.