Background: The Iron deficiency anemia is the most common form of anemia in India. Hemoglobin A1c (HbA1c) is used in diabetic patients as an index of glycemic control reflecting glucose levels of the previous 3 months. Like blood sugar levels, HbA1c levels are also affected by the presence of variant hemoglobins, hemolytic anemias, nutritional anemias, uremia, pregnancy, and acute blood loss. We conducted a study to find out the influence of iron deficiency anaemia over HbAc levels. Materials and Methods: A prospective observational study on 50 iron deficiency anaemia patient cases and 50 healthy control. Exclusion and inclusion criteria were used to recruit cases from the wards and OPDs of the hospital IN IGIMS Patna. HbA1c levels were measured at baseline and 3 months after treatment, and these values were compared with those in the control population. Results: The HbA1C was significantly higher in the iron deficiency anaemic patients as compare to the control (5.88 ± 0.41 vs 5.03 ± 0.17, respectively, P < .05). Conclusion: HbA1c is not affected by the blood sugar levels alone, and there various confounding factors when HbA1c is measured, especially that of iron deficiency, which is the commonest of the deficiency disease worldwide.rule out IDA before making a therapeutic decision, based on the HbA1c levels.