Recent research highlights that impairments in bone quality, rather than solely bone mineral density (BMD), are a significant factor in the weakened mechanical properties of bone seen in various medical conditions, including type 1 and type 2 diabetes, chronic kidney disease, cancer, and certain metabolic bone disorders. These conditions may alter bone quality without significantly affecting BMD, leading to an elevated risk of fragility fractures. Extensive studies have revealed that the BMD T-score, a widely used quantitative metric, frequently falls short in accurately predicting fracture risk. To address this, both in vivo and ex vivo methods have been utilized to assess bone quality, with a focus on structural, mechanical, and compositional characteristics. This review examines the multiscale evaluation of bone quality, emphasizing the key findings of different techniques and their respective limitations.