A 46-year-old man presented with low dorsal pain and paresthesia. Computed tomography showed an osteolytic lesion involving most of the vertebral body and the left pedicle of the 12th thoracic vertebra (T12). Contrast-enhanced magnetic resonance imaging (MRI) of the spine showed an enhancing soft-tissue mass that involved the T11 and T12 vertebral bodies, as well as that of the first lumbar vertebra; the mass caused cord compression. Another lesion was identified at T9. The findings of percutaneous needle aspiration biopsy of the lesion were consistent with metastatic astrocytoma, a diagnosis confirmed at surgery. MRI of the brain showed an asymptomatic lesion of the left temporal lobe; histologic confirmation of malignant astrocytoma was obtained by stereotactic biopsy. This report shows that metastatic bone disease secondary to malignant astrocytoma may manifest itself before the primary lesion becomes symptomatic. This presentation of astrocytoma was unusual because there were no symptoms of the intracranial tumour and because metastatic disease to the bones is less common than to the chest and the lymph nodes.