BACKGROUND. Osteoporosis with subsequent osteoporotic vertebral compression fractures is an increasingly important disease due not only to its significant economic impact but also to the increasing age of our population. Pain reduction and stabilization are of primary importance with osteoporotic vertebral compression fractures. OBJECTIVE. To compare the efficacy and safety of balloon kyphoplasty and vertebroplasty for the treatment of vertebral compression fractures. MATERIALS & METHODS. From January 2004 to December 2009, 142 patients (32 males and 110 females), from 54 to 84 years old (mean age 67.4) were treated for 185 osteoporotic vertebral fractures of the thoracic or lumbar spine (level of fracture at Th5 or lower), with back pain for more than 8 weeks, and a visual analogue scale (VAS) score of 5 or more. Twenty-two patients (29 fractures) were lost at follow-up period and excluded. Patients were randomly allocated to percutaneous kyphoplasty (64%) or vertebroplasty (36%). All fractures were analyzed for improvement in sagittal alignment (Cobb angle, kyphotic angle, sagittal index, vertebral height). The patients were evaluated using the visual analog scale (VAS) and the Oswestry Disability Score. Radiographs were performed postoperatively, and at 1, 3, 6, and 12 months. RESULTS. The score according to pain, the patient's ability to ambulate independently and without difficulty, and the need for medications improved significantly (P < 0.001) after kyphoplasty or vertebroplasty. No significant difference could be found between both groups for the mean VAS and ODI preoperative and postoperative. Vertebral body height and kyphotic