Renal vein thrombosis and adrenal hemorrhage can both be encountered in the neonatal period and they may occur at the same time. Inferior vena cava thrombosis can complicate some cases. These diseases can be easily diagnosed by means of ultrasound. The authors present 4 cases in which newborns were affected by renal vein thrombosis associated with adrenal hemorrhage and caval thrombosis, evaluated by means of ultrasound. The echographic aspect of renal, adrenal and caval involvement is described.