Estrogen-receptor positive tumours represent the majority of breast cancers in postmenopausal women. Adjuvant endocrine therapy with aromatase inhibitors (AIs), continued for up to 10 years in high-risk patients, reduces by 40% the risk of recurrence. However, this therapy, among other side effects, is burdened with a higher incidence of osteoporotic bone fractures. To date, both bisphosphonates and denosumab are recognized as first-line drugs in the primary prevention of osteoporotic fractures in patients treated with AIs. They have demonstrated their effectiveness in increasing bone mineral density and in reducing the incidence of fractures, but they have also been shown to improve disease free survival (DFS).