Vertebroplasty and vertebral kyphoplasty are increasingly performed to treat vertebral fractures, most notably those related to osteoporosis. Adverse effects are uncommon and consist chiefly of cement leakage out of the vertebral body and of vertebral fractures adjacent to the treatment site. We report two cases of vertebral osteitis adjacent to vertebroplasty sites, in a 60-year-old woman and a 79-year-old man. Kyphoplasty to treat an osteoporotic vertebral fracture was followed by acute pain with an inflammatory time pattern and laboratory evidence of inflammation. Time to symptom onset was 10 days and 45 days, respectively. Magnetic resonance imaging showed changes consistent with inflammation in an adjacent vertebra (low signal on T1 images, gadolinium enhancement, and high signal on T2 images). A biopsy of the lesion disclosed moderate nonspecific inflammation, with no microorganisms or evidence of malignancy. Both patients recovered slowly. The male patient experienced a fracture at the site of the lesion. Few cases of osteitis adjacent to kyphoplasty have been reported. The underlying pathophysiology may involve changes in vertebral loading and cement leakage into the intervertebral disk.