Background: Breastfeeding is the perfect food, but mothers should have appropriate practices to do it right. Aims: Determine the attitudes and practices on breastfeeding in postpartum women and their socio-perinatal factors associated. Methods: Cross-sectional study conducted between October and December 2012. We used a previously validated questionnaire self applied nominal response with multiple choice questions on attitudes and practices of breastfeeding. We obtained a non-probability sample of women in the birthing of Hospital Nacional María Auxiliadora. Linear regression was used for bi and multivariate analysis, obtaining the crude and adjusted coefficients with confidence intervals at 95[%]. Results: Participants 256 postpartum women, median age was 24.5 years (range 18-46 years), 25[%] had 7 good answers of the 20 raised. We found a positive correlation between higher number of correct responses and the variables of age (p = 0.002, coefficient: 0.1), number of prenatal visits (p = 0.031, coefficient: 0.1) and a negative correlation with the information received by another person who is not healthcare (p = 0.033, coefficient: -1.2). Conclusion: There is an association between attitudes and practices on breastfeeding by socio-perinatal factors, this being important for planning training programs. These results are consistent with other research showing that there is a greater increase in knowledge of pregnant women experience.