OBJECTIVES: To estimate the social determinants of young pregnancy women from poor households in a region of Colombia in 2014. METHODS: A cross sectional survey was designed and applied to collect information regarding the sociodemographic characteristics of the young poor population of seven municipalities from two Colombian states (Bolívar and Sucre). A sample of 10.677 young people with public health insurance between 10-24 years old was extracted from a simple random sampling, of which 6,006 were women. A multivariate probit model with robust standard errors was conducted to estimate the social determinants of young pregnancy in population from poor households in a region of Colombia in 2014. RESULTS: Out of the total women (6,006) between 10-24 years, 27.6% reported to have been pregnant at least once in life (32.2% were between 15-19 years old). Multivariate Probitmodel results show a pseudo R-square of 0.6015, which represents a good association among variables. The average marginal effect of the model show that when having the following characteristics; Marital status [married (β=0.44, p=0.000), divorced (β=0.6, p=0.000), cohabiting (β=0.50, p=0.000)], bad relationships with the father (β=0.03, p=0.021) and suicidal thoughts (β=0.08, p=0.004), the likelihood of getting pregnant at least once in life increase. Young people with complete education (primary, secondary or superior studies) were less likely to have been pregnant at least once. CONCLUSIONS: The acknowledgement of risks and protective factors of pregnancy in young people from Colombia can improve the effectiveness of public policies to avoid unwanted pregnancies in young women.