Histological and histochemical techniques were employed in a study of the spinal muscles from 35 adolescent scoliotic patients. Many abnormalities were found and, in general, the changes were indicative of denervation and neuropathy. None of the abnormalities were found at any one site more frequently than at any other, nor were they more often seen on one side or the other. None of the patients examined were normal at all sites of biopsy. These findings provide evidence of a neuropathic process being involved in the aetiology or progression of scoliosis. So-called "idiopathic" scoliosis may, perhaps, be the result of an otherwise sub-clinical lower motor neurone disorder.