Abstract: This study explores the feasibility of opportunistic osteoporosis screening using an artificial intelligence (AI)-based bone mineral density (BMD) measurement system on chest computed tomography (CT) scans. A retrospective analysis was conducted on 462 patients who underwent both dual-energy X-ray absorptiometry (DXA) and chest CT in our department between August 2023 and July 2024. The cohort included 317 postmenopausal women and 145 men aged > 50 years. BMD measurements from the AI system and DXA were compared. Using the T-value measured by DXA as the reference standard, the consistency and correlation between AI-based and DXA-measured BMD were analyzed. Significant differences in height, weight, DXA T-value, and AI-derived BMD were observed between men aged > 50 years and postmenopausal women. The AI-derived BMD showed a correlation coefficient of 0.767 with DXA T-values and a κ value of 0.697. The area under the ROC curve for AI-based diagnosis of osteoporosis was 0.941（95% CI 0.914–0.968), with a sensitivity of 85.71% and a specificity of 93.84%. The AI-based BMD measurement system demonstrates strong correlation and good agreement with DXA, supporting its feasibility for opportunistic osteoporosis screening.