The focus of this article is the satisfaction and health-related quality of life felt by patients with diabetes mellitus. Taking the LIVE-DE study as an example, it is demonstrated how various regimens of insulin treatment affect patient satisfaction. The standardized Insulin Treatment Experience Questionnaire (ITEQ) was produced for this purpose. It has 28 defined questions and answers. The 28 items describe in eight categories the experiences and problems which diabetic patients have had. It was found that there were significant differences between the insulin glargine and the NPH insulin-based regimens regarding quality of life and satisfaction with the treatment, a difference that ranged from small to moderate in favour of insulin glargine.