The results of a retrospective study of 24 adult patients with occult dysraphism are described. There were 15 males and 9 females, with an average age of 31.1 years. Specific circumstances precipitated symptomatic onset in 67% of patients. Pain, often referred to the anorectal region, was the most common presenting symptom. Bladder and bowel dysfunction were also common findings. The most common tethering lesions were intradural lipoma and a short thickened filum terminale. Myelography revealed the diagnosis of tethered conus in most cases, but the addition of CT and MRI images provided valuable structural details. The surgical outcome was gratifying in relation to pain and sensory-motor deficits but disappointing in the resolution of sphincter disorders. Our conclusion is that symptoms and/or signs of TCS with onset in adult life are not invariably irreversible.