A 49-yr-old male presented with paraparesis and urinary incontinence that appeared 10 min after surfacing from a dive. Treatment was started on an extended USN table 6, but the symptoms persisted. Twenty-four hours later, he was treated with oxy-helium table CX-30, resulting in marked improvement in gait and in sensory and motor function. Urodynamic examination indicated an upper motor neuron lesion; bilateral decreased amplitude of the somatosensory evoked potential was found on stimulation of the tibial nerves; no response below the upper limbs was elicited on central motor conduction time (CMCT) testing; MRI showed lesions in the lower dorsal cord. The patient's condition was further improved by an additional 10 hyperbaric oxygenation sessions, with complete restoration of urinary control and virtually complete sensory and motor recovery. Follow-up urodynamic studies were normal. CMCT recordings showed a bilateral lower limb small-amplitude response. The present case reinforces the limited clinical data regarding the value of oxy-helium in the treatment of neurological decompression sickness, even when primary treatment with oxygen tables is unsuccessful.