The aim of this study was to analyze the relationship between Alzheimer's disease (AD) and a risk of osteoporosis in the elderly cohort of Chongqing, China.A prospective study with 6 years of follow-up in 1802 patients aged 60- 75 was conducted from January 2007 to June 2013. Dual energy X-ray absorptiometry was utilized to evaluate bone mineral density (BMD). Their cognitive function was detected using the Chinese version of the Mini-Mental State Examination (MMSE) and a detection of the instrumental activities of daily living (ADL). Cox proportional hazards models were used to detect the association between AD and the risk of osteoporosis.After adjusting for age, female, AD, 25-hydroxyvitamine D (25(OH)D), smoking, drinking and stroke, AD (Hazard ratio, HR 2.48, 95%CI 1.66-2.94), age (HR 1.36, 95% CI 1.14-1.60), female (HR 1.39, 95% CI 1.17-1.65), 25(OH)D (HR1.34, 95%CI 1.11-1.59), current smoking (HR 1.27, 95%CI 1.22-1.43), daily drinking (HR 1.33, 95%CI 1.11-1.52) and stroke (HR 1.26, 95%CI 1.14-1.58) were associated with increased risk of osteoporosis. In osteoporosis fracture group, osteoporosis with AD was more common than osteoporosis with normal cognition function.AD was associated with an increased risk of osteoporosis in the elderly cohort of Chongqing, China.