We present a preterm female infant with an unusual vascular nevus on the lumbosacral and gluteal regions. Our clinical diagnosis was probable twin nevus, with a blanched nevus adjacent to a telangiectatic nevus, later complicated by ulceration. Ultrasonography and magnetic resonance imaging of the lumbosacral region revealed that her conus medullaris level was at L4 and the spinal cord was tethered by an intraspinal lipoma, without evidence of a hemangioma. We could not find any literature reporting the association of twin nevus with spinal dysraphism.