Thalassemia and related hemoglobinopathies affect the quantity and quality of haemoglobin. High performance liquid chromatography (HPLC) is considered the gold standard for diagnosis of hemoglobinopathies. This test is not available at many peripheral centers. Many formulae or indices based on complete blood counts are available that can aid in the diagnosis. The aim of the study was to analyze the reliability of these indices in distinguishing between the most common causes of microcytic hypochromic anemia i.e. iron deficiency anemia (IDA) and hemoglobinopathies. A retrospective study was performed on 2000 women who underwent antenatal screening for beta thalassemia trait (b - TT) and related hemoglobinopathies. Nine indices were calculated among both the groups using complete blood count parameters. Sensitivity and specificity of these indices to detect beta -TT versus IDA was compared. Likelihood ratio, accuracy and youden’s index for these indices were calculated. Sensitivity of Shine and Lal index was highest (98.4%) followed by Kerman 1 index (66.7%). Mentzer index, England and Fraser index, RDW index and Ehsani index each, showed high specificity (99.66%). Kerman 1 index could point towards the correct diagnosis in 97.5% of the patients. Youden index was highest for Kerman 1 index (65.4) followed by RDW index (63.1). None of the index was 100% sensitive or specific.