The importance of the nurse's role in the management of patients with type 2 diabetes has long since been emphasized. The aim of this study was to test the hypothesis that a structured organization of type 2 diabetes care, with a diabetes nurse working more independently of the general practitioner, has a significant impact on the patient's self-management and quality of care. The test consisted of 394 registered patients, all with an onset of diabetes mellitus occurring after the age of 34, at two primary health care (PHC) districts in Blekinge county in South Sweden. During one year all consultations for both doctors and nurses were analysed, and a structured telephone survey was carried out involving 364 patients who were 84 years or younger. A comparison between the two PHC centres was made regarding quality of care, frequency of consultation, patients' knowledge of their disease, and patients' self-management. The results showed that organizing care of type 2 diabetes in a structured way encourages better metabolic control in spite of less use of oral medication, and among the patients a greater knowledge of their disease and a more active self-management thus favouring implementation of local guidelines. Also, a difference was found in the patients' choice of contact with doctor or nurse regarding their diabetes and even other causes, which shifted the balance from doctor to nurse. This study provides support for organizing type 2 diabetes care in a structured way to increase the quality of care.