The terms “occult meningocele” and “spina bifida occulta” have occasioned confusion in the past. Kaufmann implies that these are more or less synonymous. Adami, however, considers “meningocele” to be a cyst of the meninges, or a hernia, projecting through the walls of the vertebral canal, and “spina bifida occulta” to be a localized lack of junction of the laminae with no projecting fluid sac. In this paper the term “occult meningocele” is employed rather than the often used “spina bifida occulta.” It embraces a diffuse dilatation of the dural sac with or without the relatively inconsequential element of herniation into the soft tissues. The meningocele, rather than the bifid spinous process, is the significant element. In one of the three cases upon which this report is based there was no spina bifida. Mixter (1), in his section in Lewis' “Practice of Surgery,” gives an excellent description of this condition, using the term “spina bifida occulta.” He describes it as a congenital malformation consisting of a defect in the closure of the vertebral arch, usually with an associated defect of the meninges and nerve tissues. He also states that, although there is no external meningeal sac, there is frequently a localized growth of hair. This was not present in any of our three cases. Mixter also adds that there is almost invariably a congenital lipoma either just beneath the skin or in some of the deeper structures. This was not true of our single operative case. In this same article the anatomical and pathological basis for the usual symptomatology is presented, and to this presentation the reader is referred for greater detail. In brief, Mixter describes one defect which is almost constant, the fusion of the central portion of the cauda equina into a single irregular bundle, which may be the site of various pathological processes comprising the nerve roots and causing disturbance of function. He mentions lipomata, dermoid cysts, and a band of dense connective tissue. Mixter also states that there are two types of history: one in which paralysis has been present since birth and one in which symptoms came on in later life. In one of our cases, the symptoms were precipitated in middle life by an injury which evidently affected the thin bony shell over the sac (Case III). The usual striking symptom is lack of bladder control, present in two of our cases, absent in the third. Occasionally, there are toe drop and a saddle anesthesia. Enderle (2), in 1932, demonstrated an occult intrasacral meningocele by myelography, which he thought was the first to be described in the roentgen literature. The patient was a forty-seven-year-old woman with pain radiating down the posterior surfaces of both legs. Plain films showed a large sacral hiatus and lumbarization of S-1. A normal cul-de-sac was demonstrated on immediate examination. Twenty-four hours later the oil descended into a lower sac, 7 × 4 × 2 cm., which was united to the lumbar sac by a narrow isthmus.