Fifty years ago type 2 diabetes mellitus was very rare in Greenland. Recent epidemiological studies have found a high prevalence of diabetes among Greenlanders comparable to levels among Inuit populations in Canada and Alaska. In 2008 a national diabetes programme was implemented aiming to improve the care for patients with type 2 diabetes mellitus in Greenland based on a donation from Novo Nordisk A/S to the national health care service. A diabetes concept based on national guidelines, systematized recording in an electronically medical record and feedback to the clinics were used to improve the diabetes care. The overall aim of this thesis was to evaluate if implementation of a diabetes programme in Greenland would have a measurable effect on the quality in diabetes care including diagnostic activity and screening for diabetic complications. Two observational and cross sectional studies were performed in Greenland 2008 and 2010 before and after implementation of the diabetes programme. The medical records of patients with diabetes were reviewed. The prevalence was estimated using the whole adult population in Greenland as background population. The quality of the diabetes care was monitored by 12 health care indicators. The prevalence of diagnosed cases with type 2 diabetes mellitus among Greenlanders has increased over a period of two years. In the same period a significant increase in the quality of care in diabetes in Greenland has been documented concerning all process-of-care indicators. Significantly regional variation in the diabetes care was demonstrated in 2008. The quality in the diabetes care was best in clinics with a database. In 2010 a more homogenate quality among the clinics in the diabetes care was demonstrated. These effects could be a result of the diabetes programme implanted in between the two observations. In conclusion, improved quality in the diabetes care along with an increasing prevalence of diagnosed type 2 diabetes mellitus has been documented after implementation of a diabetes programme. It is strongly recommended to maintain focus on the quality on the diabetes care in order to benefit from the programme in a long-term perspective.