Background: Gestational diabetes mellitus (GDM) is associated with hypertension, preeclampsia, stillbirth, macrosomia, unexplained intrauterine death, instrumental and traumatic delivery leading to both maternal and foetal injuries, and increased risk of maternal and neonatal infections. The present study was conducted at Rajendra Institute of Medical Sciences, Ranchi to determine the prevalence of Gestational Diabetes Mellitus(GDM) and its associated risk factors in tribal population of Jharkhand. Aims and Objectives: The aim of the study was to determine the prevalence of GDM and to analyze its association with various risk factors. Materials and Methods: Detailed history of all patients was taken with emphasis on genetic and family history and history of the previous pregnancies. All the patients were screened by the single step 75 gm 2 hours oral glucose tolerance test (OGTT) as recommended by the World Health Organization. GDM was diagnosed if 2 hours PG is ≥140 mg/dL. Results: Most patients of GDM were from upper middle class 45.45%, followed by lower middle class (27.27%) and upper lower class (18.18%). For the non-GDM patients, most patients were from upper lower class (55.055%), followed by upper middle (24.71%). The prevalence of GDM was 12.12 % in the tribal population as compared to non-tribal population (10.44 %). In present study, in majority (89.00 %) of study subjects, result of 75 gm OGTT was negative. Result of 75 gm OGTT was positive in only 11 out of 100 study subjects (11.00 %). Conclusion: Tribal population in Jharkhand has very poor access to health-care services of the state. This study is first of its kind in our state which will set as an eye opener to further deliver better health-care facilities at grassroot level in Jharkhand.