Chronic obstructive pulmonary disease (COPD) appears to be associated with osteoporosis. The aim of the study was to evaluate the prevalence of osteoporosis risk (OP risk) in a sample of patients with COPD. In 3030 patients (1768 men and 1262 women) aged >50 yr, we evaluated COPD severity with spirometry and OP risk by using a quantitative ultrasound device. We analyzed several risk factors for osteoporosis, such as age, gender, body mass index (BMI), fracture history, smoking status, glucocorticoid (GC) treatment in univariate and in multinomial logistic regressions. The risk of osteoporosis was higher in women and in older participants, among those with more severe COPD, treated with GC. In multivariate analysis, we found interactions between fracture history and smoking and between age and gender. Significant associations were found with BMI and GC treatment, whereas only a tendency, not statistically significant, was found for very severe COPD being associated to high risk of osteoporosis. In COPD patients the risk of osteoporosis is high, in particular at severe stages of the disease, but seems to be due to traditional risk factors, such as older age, female gender, low BMI, history of smoking and fractures, GC treatment.