The case of a combined intra- and extraspinal neurenteric cyst in an infant is reported. This case is unique because an intraspinal cyst was not suspected clinically until large numbers of squamous epithelial cells were obtained at lumbar puncture performed as part of a workup for a septic entity. The cyst extended from an intradural location ventral to the conus medullaris at L-1 through a ventrolateral defect in the S-4 vertebral body to communicate with a large presacral component. The entire cystic cavity was lined by stratified squamous epithelium. The possible pathogenesis of this lesion is discussed.