In 1950 Vincent Vermooten was the first to postulate the scientific rationale for nephron sparing surgery (NSS) in the treatment of renal cell carcinoma (RCC) [1] . But the role of NSS was subsequently challenged by the results of Robson et al on radical nephrectomy (RN) in 1969, and RN has been considered for many decades, the standard treatment for renal tumors [2, 3] . And the indications of NSS for renal tumors remained either absolute indications, in which RN will leave the patient anephric (including a solitary kidney and bilateral renal tumors) or relative indications, include impending or existing renal failure [4] . A second interest in NSS for localized renal tumors with normal contralateral kidney had been growing, creating elective indications. This occurred due to several factors including: increase in incidentally discovered renal tumors which tend to be smaller, improvement in surgical techniques and methods to prevent ischemic renal injury, better post operative care, and the fact that NSS had comparable results and complications to RN in treatment of localized renal tumors [3, 5] . In addition, better understanding of the effect of preservation of renal parenchyma on the risk of developing future chronic renal insufficiency [6] , the need for preservation of renal parenchyma if possible for later metachronous tumors on the contralateral side [7] , and the need for surgical intervention for various benign lesions [7] . The aim in applying NSS in elective indication is to preserve the maximum amount of normal unaffected renal parenchyma without compromising the oncological outcome, but the maximal diameter of a tumor suitable for this procedure remains controversial [8] . Several studies restrict the elective indication of NSS for tumors less than 4 cm in diameter [9, 10] , however other recent studies have proposed to widen the indications to