The aim of this study is to determine the risk factors of obesity among pregnant women in Biringkaya sub district at Makassar city. The study type was case control study design with pregnant women who had medical record in public health centres (Puskesmas) Sudiang, Sudiang Raya and Paccerakkang in year 2014- 2015 as subject. The body mass index (BMI) tool is used in order to measure the index of weight for height as to classify underweight, overweight and obese adults. Total samples were 152 pregnant women with 38 cases and 114 controls. The samples were obtained by using exhaustive sampling technique for case group and purposive sampling techniques for control group. The result found Odds Ratio (OR) of obese pregnant women is influenced by age (OR= 4.632; CI 95% = 2.119-10.126), parity (OR=3.107; 95% CI = 1.262-7.649), family background (OR=3.4; 95% CI= 1.578-7.527), socioeconomic status (OR=3 .612; 95% CI= 1.189-10.973) and attitude (OR= 0.838; 95% CI = 0.401-1.753). In conclusions, pregnant women's age ≥ 35 years old, parity ≥ 35, family history, high socioeconomic status are risk factors contributing towards obesity among pregnant women.