Prevalence of gestational diabetes varies from 3.8 to 21% in different parts of the country. The aim of this study was to determine the prevalence of GDM and to compare the occurrence of GDM in normal antenatal women and the women with risk factors for GDM and to assess the need for universal screening of antenatal women for GDM. METHODS: 200 pregnant women with their estimated gestational age between 24-28 weeks attending antenatal clinic in a tertiary care hospital in Guntur, South India were enrolled in the study. Women were given a standardized 75 gm Oral Glucose Tolerance test irrespective of their fasting or non-fasting state and plasma glucose was estimated at 2 hours (DIPSI criteria) and all women with a plasma glucose of ≥ 140 mg/dl were diagnosed to have GDM. A proforma containing general information on demographic characteristics like age and parity, risk factors like age more than 30 years, Obesity, family history of diabetes mellitus, past history of fetal loss, past history of congenital anomalies, prematurity, previous history of GDM, unexplained fetal loss, history of preeclampsia and polyhydramnios were noted and a comparison was made in between group 1-those with risk factors and group 2-those without risk factors to infer regarding the association of risk factors and GDM. RESULTS: A total of 200 women participated in the study, GDM was diagnosed in 5(2.5%). GDM was more common in the age group of 28 ±3.57 years, in antenatal women with higher parity, in women with a family history of diabetes. Of those testing positive, 20% of women had no risk factors for GDM and 80% had more than one risk factor for GDM. CONCLUSION: The prevalence of GDM was found to be 2.5% in a tertiary care hospital in Guntur, South India. Women with risk factors for diabetes had a higher prevalence of GDM and there is a role for universal screening as 20% of the GDM patients would be missed if selective screening is done. Large population based studies are needed in the antenatal women to know the prevalence of GDM in the community.