Introduction: Diabetes Mellitus (DM) refers to a group of common metabolic disorder. It is a chronic illness, complex requiring continuous medical care with multifactorial risk reduction strategies beyond glycemic control. HbA1c which is primarily used as a test of glycemic control & as adiagnostic test. One condition that effect erythrocyte turnover is anemia. Vitamin B12 deficiency and iron inhibit erythropoiesis and increase the mean survival duration of erythrocyte, leading to increase HbA1c. Methods: The study was conducted in tertiary care hospital, JLN Medical college Ajmer. The study involved 180 patients out of which 60 were of Iron deficiency anemia and remaining 60 had Vitamin B 12 deficiency anemia. Permission was taken from the ethical committee before starting the study. A well informed written consent was taken prior to the study and the results of the same were compared with 60 non anemic, non diabetic controls using ANOVA and T test analysis. Results: Out of 60 participants in each group, 36.67% were male and 63.335% were female in iron deficiency group, 53.33% were male and 46.67% were female in vitamin B12 deficiency group, 60% were male and 40% were female in control group. In Iron deficiency anemia 20 out of 60 participants (33.33%) had Hba1c in the range of impaired glucose homeostasis(5.6 –6.5)2 and in Vitamin B12 deficiency anemia 24 out of 60 participants (40%) had Hba1c in the range of impaired glucose homeostasis. Interestingly 4 patients from iron deficiency anemia had Hba1c in diabetic range (more then 6.5). Our study reported significant negative trend when Hemoglobin was compared with HbA1c in patients with iron deficiency anemia, that is, patients with lower Hemoglobin had higher HbA1c.Conclusion: Anemia and Diabetes are a common problem in Indian scenario and use of HbA1c to diagnose prediabetes and diabetes in iron–deficient populations may lead to a spuriously exaggerated prevalence of prediabetes.