The aim of this study is the biometrical and morphological evaluation of the ovaries by sonography and the study of the haemodynamics of the ovarian artery flow by doppler ultrasound in 14 girls with precocious puberty and in 33 control subjects. All people ranged in age from 5 to 7 years. The gonadian mean volume and the mean pulsatility index have been evaluated. A significant difference in the ovarian volume has been found between patients and controls. No index between the two groups. We conclude that the doppler ultrasound needs a larger number of cases to evaluate its validity in girls with precocious puberty.