A total of 187 random cases of untreated idiopathic scoliosis, seen from a minimum of 15 to a maximum of 47 years after the end of growth, were reviewed. All curves increased after skeletal maturity (average progression: 0.4° per year). Thoracic curves tend to progress more than lumbar, lumbar more than thoracolumbar, and thoracolumbar more than double major curves. Pain was present in 114 cases (61%) and appeared more frequently in women, after pregnancies, and with fatigue. Cardiopulmonary symptoms were present in 42 patients (22%), especially those with thoracic and thoracolumbar curves greater than 40°. Psychologic disturbances were found in 35 cases (19%), mostly female patients with thoracic curves greater than 40°. The cosmetic appearance of these patients at long-term follow-up was better compared with that at the end of growth, even though the curves progressed. Patients with decompensation of the trunk at the end of growth seemed to improve with time. In an unselected group of patients with severe curves a mortality rate of 17% was found, twice as much as in the Italian general population.