The objective of the present study was to describe the changes in glycaemic control based on data from the nationwide Danish Registry of Childhood Diabetes with valid haemoglobin A1c (HbA1c) readings centrally analysed between 1996 and 2006. The glycaemic control was assessed using generalized linear mixed models. Centre, age, diabetes duration, ethnicity, sex, self-monitoring of blood glucose, insulin regimens and hypoglycaemia was tested as explanatory variables. There were 9291 HbA1c recordings from 2705 children with T1D during the 10-yr period. The unadjusted mean HbA1c value in 1997 was 9.05% (95% CI +/- 0.82) and in 2006 was 8.20% (95% CI +/- 0.06). Mean HbA1c was significantly reduced over the years with a linear decrease of 0.08% per year (95% CI +/-0.011) (p < 0.0001). The decrease was unaffected by adjusting for number of injections, insulin/kg and use of insulin analogous. During the period, an increased frequency of self-monitored blood glucose was observed that was associated with a reduction in HbA1c (p < 0.0001). The percentage of children with severe hypoglycaemia decreased from 12.2 to 7.8% in those with HbA1c between 6 and 8%. Metabolic control in diabetic children has improved on a nationwide basis from the establishment of the national registry in 1996. The reduction in HbA1c was related to an increased number of self-monitoring of blood glucose values and a decrease in the number of hypoglycaemic events in those with the best metabolic control, whereas there were no association with the use of new analogous or insulin regimens.