Background and aims: Osteoporosis and metabolic syndrome (MetS) are conditions associated with ageing and chronic inflammation; among MetS’ components, visceral obesity has been correlated to low bone mineral density in postmenopausal women. However, data on an increased fracture risk in MetS are still contrasting. The trabecular bone score (TBS), a DXA-derived imaging technique, is an indicator of bone quality and a potential predictive factor for fractures independent of body mass index. The aim of this study was to explore the relationship between MetS components and TBS. Methods: The study population consisted of 3962 female subjects ≥20 years recruited in the 2005-2006 and 2007-2008 National Health and Nutrition Examination Survey (NHANES) cohorts, for whom a valid TBS value was available. All analyses were adjusted for menopausal status and other traditional risk factors of altered bone mineralization and metabolism. Results: 34.3% of study subjects had TBS below the normal threshold. An inverse significant association was observed between TBS and most of the MetS variables investigated, with the strongest correlation found with waist circumference (WC) (p<0.001). WC represented the major predictor of degraded TBS (p<0.001), in adjusted models considering age, 25 (OH) Vitamin D, smoke and insulin resistance. Furthermore, increased WC was significantly associated with the presence of bone fractures at the logistic regression analysis (p=0.001) in all study participants and in the sub-group of women ≤50 years old, after adjustment for potential confounders (p=0.006). Conclusion: This study, using a large sample of women, found a strong link between waist circumference and degraded bone health, particularly in women under 50. The negative impact of metabolic syndrome on bone health is mainly driven by WC and abdominal obesity. The results underscore the importance of maintaining a healthy lifestyle, including weight control, to positively influence bone health and reduce the risk of fractures in younger women.