Background: GDM is defined as impaired glucose tolerance first diagnosed during pregnancy. The prevalence of GDM is increasing due to increased obesity and is estimated globally to be 14%, varying between 1% and 28% depending on ethnicity, screening methods and diagnostic criteria. Polycystic ovarian syndrome (PCOS) is the most common endocrine disorder that affects women of reproductive age with a prevalence of 12–21%, and it has a profound impact on the psychological, reproductive and metabolic health of women. the present study aims to find the correlation between BMI, lifestyle and PCOS with gestational diabetes. Aim & Objectives: To study the correlation of BMI, lifestyle and Polycystic Ovary Syndrome with Gestational Diabetes. Material and Methods: A hospital basedobservational study was conducted among 200 antenatal females in Muzaffarnagar Medical College & Hospital, Muzaffarnagar, Uttar Pradesh. Study was conducted for 12 months.Data was analysed statistically and chi square test was applied. Results: 42% of the women were aged 25-30, and 34% were aged 20-25. The majority (62%) were primigravida. 39.5% had a normal BMI, 34% were overweight, 15% were obese, and 11.5% were underweight. 11% were smokers. Additionally, 20.5% of the participants had a family history of gestational diabetes mellitus (GDM). Lastly, 28% of the participants had polycystic ovary syndrome (PCOS), and 72% did not. 37% had GDM. There was highly statistically significant association between BMI, smoking habits and PCOS with GDM. Conclusion: The present study identified significant correlations between higher BMI, smoking habits, and the presence of PCOS with the incidence of Gestational Diabetes Mellitus (GDM) among the participants, highlighting the need for targeted interventions to manage these risk factors and reduce the risk of GDM in these populations.