The etiology of obesity is complex and includes genetic, environmental, cultural and socioeconomic factors. The World Health Organization revealed that 39% of women of reproductive age are overweight, which has a direct impact on the increase of pregnancies with risk of perinatal morbidity and chronic noncommunicable diseases. The aim of the study was to characterize the sociodemographic factors and their relationship with body mass index in a population of pregnant women in a referral health center in Cali in the period between November 2018 and January 2019.