Introduction. Breastfeeding is the healthiest way to feed newborns and infants. The composition of breast milk is optimally matched to the needs of young children; it therefore ensures the best protection and provides many health benefits for the baby and mother. It is important for women to be aware that even a short period of natural breastfeeding has many health benefits for both the baby and the mother. Aim. The purpose of the study was to assess the level of knowledge of women about the benefits of breastfeeding and to identify the sources of that knowledge. Material and method. 681 female respondents were included in the study. The study was conducted with the use of a questionnaire designed by the author of the research. Results. The respondents had an average level of knowledge of the benefits of breastfeeding (PW=0.66). The highest average level of knowledge was recorded in the following aspects: the effect of breastfeeding on: the shrinking of the uterus after delivery (PW=0.94); adequate bacterial colonization in the intestines of the newborn (PW=0.93); establishment of an emotional bond between the mother and baby (PW=0.92). The largest number of the respondents derived their knowledge about the benefits of breastfeeding from websites (84.1%). More professional sources of knowledge, such as scientific books/ journals (57.1%) or direct contact with medical personnel (50.7%), turned out to be much less popular. Less than half of the respondents used specialized forms of support, e.g., birth schools, and only 28.2% used lactation clinics. Conclusions. – Women have average knowledge of the benefits of breastfeeding. – Women have the greatest knowledge of breastfeeding in terms of its effect on the contraction of the uterus after birth, its impact on the proper colonization of the intestines with the appropriate bacterial flora in the newborn, and its influence on the formation of an emotional bond between a mother and her child. – Sociogeographic factors do not differentiate the subjects in terms of their level of knowledge about breastfeeding. – The most common sources of knowledge regarding breastfeeding are websites and social media.