The results of a study on 50 patients with Turner syndrome, all of them older than 14 years and never treated, are reported. In order to correlate karyotypes and clinical manifestations of the syndrome, we performed a complete physical examination and ultra sonographic tests of the heart, kidneys, uterus and ovaries. We found a better spontaneous growth and sexual maturation in mosaic 45.X/46.XX patients than in patients with 45.X and X structural anomalies. No differences were found in heart and kidney congenital anomalies between groups of patients with different karyotypes. We conclude that the presence of an XX-line has an ameliorating effect on height and gonadal function of patients with Turner syndrome.