Although pregnancy and breast-feeding involve adequate calcium mobilization, it is not recognized if these affect the acquisition of a healthy peak bone mass (PBM) and, hence, postmenopausal osteoporosis (PMOP). The aim of this review was to evaluate osteoporosis in postmenopausal women and its association with breastfeeding. Searches were conducted in PubMed Central and Scopus to find relevant literature and studies. Searching terms were “osteoporosis” AND “breastfeeding. There was no time restriction applied. Language was restricted to English, German and Greek. Results from different studies evaluating the association of breastfeeding and osteoporosis in women are contradictory. While some show a beneficial and protective effect of breastfeeding, others show a detrimental impact and some studies show no association at all. Postmenopausal osteoporosis (PMOP) has long been a pervasive public health concern and the prevention, assessment and management of postmenopausal osteoporosis is particularly important. Thus, more research is needed on the association of breastfeeding and osteoporosis to be able to give accurate recommendations to women.