Osteoporosis is a bone disease that promotes the development of fragility fractures. An algorithm is proposed for the gynaecologists'use to diagnose and treat osteoporosis in young menopausal women. The fracture risk can be calculated with the FRAX tool. If the 10-year fracture risk is ≥ 10 %, a bone densitometry is recommended, and the result is integrated in the FRAX tool. If the risk is between 10 and 20 %, a treatment should be discussed individually and, in some cases, a pharmacologic preventive treatment, by menopause hormonal treatment or SERMs, can be initiated. A pharmacologic treatment (bisphosphonates or dénosumab) is recommended in case of previous fragility fracture or risk ≥ 20 %, independently of a T-score < -2.5 DS. Patients have to be referred in case of treatment failure or intolerance, and at the end of any denosumab therapy.