Objective-To try to start insulin therapy in elderly non-insulin-dependent diabetes mellitus (NIDDM) patients with secondary failure in primary health care, and compare costs for starting treatment in a health care centre and in a day-care clinic in a hospital.Design-Time and costs for start of insulin were calculated.Setting-A health care centre in Stockholm, Sweden.Subjects-Fourteen consecutive patients in the health care centre and a control group of 14 patients in the day-care clinic.Results-Metabolic control in both groups improved significantly. Total time spent with the district nurse to start insulin treatment was 3 hours during about 7 weeks with a total cost of SEK 1100 in the health care centre. In the day-care clinic patients were admitted 5.6 days with a total cost of SEK 6100–10 900.Conclusions-Elderly patients can learn the injection technique and manage insulin therapy, which results in good metabolic control. Insulin treatment can be started in primary health care. With elderly patients it takes time, but it is far more cost-effective in primary health care than at the hospital.