After a critical study of the methods in use for the lithiasis surgery of the kidney; the great risk of some of them, the inefficacy and the danger–especially in the staghorn cases, the calicial stones or those contained in a pelvis of intrarenal type–are pointed out. The causes due to the operative lithogenic disease are analysed. The submitted new surgery for the renal lithiasis is based upon the combined and simultaneous utilization of several principles–some known, such as the surgery of the kidney ‘in situ’, others modified, such as the posterior vertical lumbotomy replacing the classic and dangerous oblique lumbotomy, and finally some new ones, such as: the extracapsular approach to the renal sinus, the transverse intrasinusal pyelotomy incision and the selective calicotomy incision. The exposure of the renal sinus by this new extracapsular approach is technically easy and offers visibility to all the intrarenal portion of the pelvis and to the major calices. It is completely bloodless. For several reasons the transverse intrasinusal pyelotomy is far superior to the classic vertical pyelotomy. The intrasinusal calicolithotomy is also a new term which must enter into the nomenclature and practice of urological surgery. The postoperative stage elapses with no leakage of urine so that drainage of the lumbar fossa is omitted thus avoiding complications. Patients leave the hospital by the seventh, and many by the fourth day after the operation. This type of surgery has changed the prognosis for staghorn calculi and multiple calculi cases obtaining a total extraction with no injury to the renal parenchyma, and no trauma to the excretory tract. It is of great advantage to the patient who carries a simple pelvic calculus. Following this kind of operation reinterventions do not offer inconveniences, but then, the sinusal space must be entered by way of another approach, the intracapsular one. The number of recurrences is notoriously lower than those observed with the classic techniques. Our conclusions are based on an experience of 324 cases of no mortality, no complications and with excellent results.