Review of the literature shows that the cause of idiopathic scoliosis remains unknown, although research has possibly eliminated some hypothetical causes. Abnormalities of disc, bone, muscle, and collagen do not appear to be etiological factors but, rather, reflect the effects of scoliosis on normal tissues. Although most patients with idiopathic scoliosis are thought of as tall and slender, it has not yet been proven that growth in this condition differs from normal. It is possible that idiopathic scoliosis is caused by multiple factors rather than a single factor. Perhaps there are different factors for curve initiation and curve progression. It appears that a brain stem or equilibrium abnormality does exist in patients with idiopathic scoliosis, although more research is needed to confirm and define the problem. There also may be a genetic basis for idiopathic scoliosis, as it does seem to occur within patients' families more frequently than in the general population. Whether these two factors form the basis for a multifactorial etiology of idiopathic scoliosis remains to be proven.