Background:Gestational diabetes mellitus (GDM) is a metabolic disorder defined as glucose intolerance with the onset or first recognition during pregnancy. Women with GDM are at increased risk for adverse obstetric and perinatal outcome. The complications associated with GDM can be prevented by early recognition, intense monitoring and proper treatment.Aims:The present study was done to screen the high-risk pregnancy group for GDM, to find the incidence of abnormal results on screening and to correlate the abnormal results with the maternal and fetal outcomes. The study was done in a tertiary care hospital and teaching institute. It was a prospective cohort study.Materials and Methods:Selective screening for GDM was done in 150 pregnant women with high-risk factors. Screening was done with 50 g glucose challenge test (GCT) after 18 weeks, and if GCT was negative then the test was repeated after 28 weeks of pregnancy. The patients who were having an abnormal GCT were subjected to 100 g oral glucose tolerance test (OGTT). All GDM patients were followed up and treated with diet and/or insulin therapy till delivery to know maternal and fetal outcomes. The period of study was from April 2008 to March 2009.Results:7.3% of study population was OGCT positive. 6% of the study population was OGTT positive. Age >25 years, obesity, family history of DM, and past history of GDM were the risk factors significantly associated with GDM. One newborn had hypoglycemia and one had hyperbilirubinemia. The fetal and maternal outcome in GDM patients was good in our study due to early diagnosis and intervention.Conclusion:Women with GDM are at an increased risk for adverse obstetric and perinatal outcome. The increased morbidity in GDM is preventable by meticulous antenatal care.