Hyperprolactinemia may cause bone loss but data on fractures are scanty. The aim of this study was to evaluate the prevalence of vertebral fractures in women with prolactin (PRL)-secreting adenoma. In this cross-sectional study, 78 women (median age 45.5 years, range: 20-81) with PRL-secreting pituitary adenoma (66 with microadenoma and 12 with macroadenoma) and 156 control subjects, with normal PRL values and with comparable age to patients with hyperprolactinemia, were evaluated for vertebral fractures by a morphometric approach and for bone mineral density (BMD) by a dual-energy X-ray absorptiometry at lumbar spine. Vertebral fractures were shown in 25 patients with PRL-secreting adenoma (32.6%) and in 20 controls (12.8%, P < 0.001). Fractured patients were significantly older (P < 0.001) and had lower BMD T-score (P < 0.001), longer duration of disease (P < 0.001), higher serum PRL (P = 0.004) and lower serum IGF-I (P < 0.001) values as compared to patients who did not fracture. The prevalence of vertebral fractures was significantly (P < 0.001) higher in post-menopausal women with PRL-secreting adenoma as compared to pre-menopausal patients. Fractures occurred more frequently (P = 0.01) in patients with untreated hyperprolactinemia versus patients treated with cabergoline. Logistic regression analysis demonstrated that duration of disease maintained a significant correlation with vertebral fractures (odds ratio 1.16, C.I. 95% 1.02-1.33) even after correction for age, menopausal status, treatment with cabergoline, BMD, serum IGF-I and serum PRL values. Hyperprolactinemia is associated with high prevalence of radiological vertebral fractures in women with PRL-secreting adenoma.