Introduction: Diabetes Mellitus (DM) is a metabolic condition linked by the inability to produce enough insulin and/or to respond to insulin. This can lead to a number of acute and chronic health problems. In erythrocytes, transferrin is the main source of iron. Alterations in transferrin glycation affect transferrin saturation because the affinity of transferrin for Fe3+ is extremely high but it decreases progressively with increasing glycation. Aim: To investigate the influence of uncontrolled diabetes on transferrin glycation and iron metabolism. Materials and Methods: A total of 136 samples from 3 groups of HbA1c levels (<6.0% non-diabetic, 6.4-8% diabetic, >8.0%-uncontrolled DM) were studied for the correlation pattern of iron with other variables. Chi square test and student’s t-test were performed to reveal the association between serum free iron levels and other variables with DM. Results: Serum iron has shown to be depleted significantly (p=0.02) along with percentage saturation (p=0.0006) with increase in diabetic severity. No significant differences were observed in serum ferritin in controlled DM and uncontrolled samples. Total Iron Binding Capacity (TIBC) was found to be significantly increased in uncontrolled DM samples (p=0.01). Abnormal transferrin was observed uncontrolled diabetes with subsequent depletion in transferrin, which in turn results in low serum iron, lower percentage saturation and high TIBC. Conclusion: Uncontrolled diabetes affects the glycation of transferrin also thus perturbating iron metabolism. The present study emphasises the need to monitor transferrin glycation status and iron deficiency anaemia in subjects with uncontrolled diabetes.