75 patients (33 male, 42 female) with congenital scoliosis, diagnosed first time between birth and 40 years were examined. Type and site of the anomaly were classified and evaluated in accordance with a standardized scheme. The prognosis of congenital scoliosis depends strongly on the type of the anomaly. The differences of progression in the site of the abnormality are therefore minor. Unilateral unsegmented bars showed the most severe progression: the yearly rate of deterioration of the curve averages 7.6 degrees. Unilateral hemivertebrae showed 1.5 degrees (upper thoracic region) and 2.3 degrees (lower thoracic region). Two contralateral hemivertebraes and block vertebraes had a yearly rate of deterioration less than 1 degree. Operation is the treatment of choice in case of unilateral unsegmented bars. A conservative treatment is sufficient in most cases of other abnormalities.