Introduction In 2008, the UK National Osteoporosis Guideline Group (NOGG) produced a guideline on the prevention and treatment of osteoporosis, with an update in 2013. This paper presents a major update of the guideline, the scope of which is to review the assessment and management of osteoporosis and the prevention of fragility fractures in postmenopausal women and men age 50 years or over. Methods Where available, systematic reviews, meta-analyses and randomised controlled trials were used to provide the evidence base. Conclusions and recommendations were systematically graded according to the strength of the available evidence. Results Review of the evidence and recommendations are provided for the diagnosis of osteoporosis, fracture-risk assessment, lifestyle measures and pharmacological interventions, duration and monitoring of bisphosphonate therapy, glucocorticoid-induced osteoporosis, osteoporosis in men, postfracture care and intervention thresholds. Conclusion The guideline, which has received accreditation from the National Institute of Health and Care Excellence (NICE), provides a comprehensive overview of the assessment and management of osteoporosis for all healthcare professionals who are involved in its management.