Objective: Identify socio-demographic and fertility factors, associated with the occurrence of unintended pregnancy in Colombian women of reproductive age in 2010.Methods: A retrospective cross-sectional study, based on data ENDS Colombia 2010 on the total number of women of childbearing age (13-49 years) that at the time of the survey were in pregnancy was performed. The main outcome was unintended pregnancy, it was described the study population and the possible association with sociodemographic and fertility variables, through bivariate and multivariate analyses. Additionally, were performed the same analysis stratified by age group (adolescents vs. adults).Results: The prevalence of unintended pregnancy in Colombian women in 2010 was 61.4%. . According to the logistic regression model, not be with a partner (OR: 4.01 95% CI: 3.066 to 5.269), having previous children (OR: 2.040, 95% CI: 1.581 to 2.631), being in quintile 1 wealth (OR: 2.137, 95% CI: 1.328 to 3.440), and being a teenager (OR: 1.599, 95% CI: 1.183 to 2.162) are factors that increase the likelihood of having an unintended pregnancy. In addition, differences in the associated factors were found when stratified analyses were performed by age.Conclusions: The prevalence of unintended pregnancy in Colombia remains high compared to previous years and other countries. The results of this study may be useful for developing and setting policies of sexual and reproductive health taking into account the associated factors identified giving priority to adolescent and low socioeconomic status in order to prevent the unintended pregnancy in Colombia.