Diabetes is one of the common diseases of 21st century. Long standing Diabetes is one of the risk factor for development of all microvascular complications of diabetes. HbA1c variability is an independent risk factor for the same. Cardiovascular autonomic neuropathy is present in 16-40% of diabetic population. High QTc indicates a dysfunction of the autonomic system of heart in patients with DM. In our study 75 adults with duration of diabetes longer than 5 years were randomly selected, their HbA1c measured and correlated with QTc interval. Analysis showed that ECG changes (blocks or ischemia) were present in 22.6 % of subjects. And the mean QTc interval was 397ms. Correlation crosstabs between QTc and Hba1c showed strong positive correlation (pearson correlation =0.677, p value =0.001) between HbA1c and QTc. The study demonstrates that there is strong positive correlation between HbA1c and QTc interval suggesting high incidence of microvascular complications in patients with high HbA1c.