It has been widely accepted that the neurologic sequelae of decompression illness are confined to the spinal cord. Of 10 divers who gave a history of an episode of decompression illness involving the central nervous system, we found that eight had unequivocal neurologic deficits implicating multiple supraspinal lesions. Seven of these neurologically impaired divers completed a battery of neuropsychologic tests that revealed severe deficits in all cases. The findings show that diffuse and multiple central nervous system lesions result from decompression illness and demonstrate the importance and close correlation of thorough neurologic and neuropsychologic tests in assessment following diving accidents.