The advantages of, and the two-year experience from, ultrasonographically controlled percutaneous nephrostomy are analyzed. Nephrostomy was performed under control by a Brüel-Kjaer type 1846 ultrasonographic apparatus which established compression anuria of tumorous origin, septic state owing to ureteral occlusion and solitary nephrolithic occlusion among the pathogenic causes. The advantages include speed of performance, minimum strain imposed on the patient as well as the possibility in tumorous anuria to create a definite urinary bypass.