Breastfeeding is a natural feeding act, but, at the same time, it is a learned behavior. The objective of this study was to evaluate the level of knowledge of mothers and pregnant women after applying an educational strategy in Venezuela. An evaluative, cross-sectional investigation was conducted in 2015 among 1.132 pregnant women and mothers of children under two years of age who were apparently healthy. The degree of knowledge before the intervention was measured through a pre-test. Subsequently, educational workshops were held on breastfeeding topics: benefits, physiology, nutritional contributions of breast milk, conservation and storage of breast milk, breastfeeding techniques, laws that protect the practice, after which, the test was applied again. For the processing and analysis of the information, the statistical program SPSS 19.0 was used. The knowledge level increased from 28.8% (deficient) to 60.8% (good). We also observed a significant correlation (p<0.05) in the number of correct answers before and after the test. The topics that had the greatest impact were: milk conservation, breastfeeding practice and measures to increase milk production. In conclusion, mothers and pregnant women improved their knowledge of breastfeeding issues due in part to the impact of the educational activities undertaken.