We reviewed records of 79 men with spinal epidural metastases diagnosed from July 1984 to July 1989, imaged by myelography or MRI, and treated with radiation therapy. Thirteen men (16%) had second epidural metastases. The mean time between lesions that developed within two vertebral bodies of a prior lesion was 2.8 months, compared with 15.2 months for lesions that were three or more vertebral bodies from a prior lesion. Some secondary spinal metastases occurring soon after the initial metastasis may represent regrowth of tumor at the border of the radiation port, suggesting that larger radiation ports be constructed for patients with lengthy expected survival times.