This study report the long-term results of 504 patients who underwent nephron sparing surgery (NSS) for cancer suspicious, solid renal tumors in the presence of a normal opposide kidney. A total 715 patients underwent NSS since 1969, including 504 for an elective indication, that is with a normal opposite kidney. Of these patients 381( 75.6% had RCC, 123 (245.4%)had cancer suspicious benign lesions, including 53 (10.5%) with oncocytoma. 33 (6.5%) with angiomyolipoma, 23 (4.6%) with complicated cyst and 13 (2.8%) with other benign lesions. Of the 381 patients with RCC 283 (74.3%) had clear cell, 68 (17.8%) had papillary and 30 (7.9%) had chromophobic RCC. Mean tumor diameters was 3.0 cm ( range 0.5-11.0). Mean followup was 6.77 yeras ( range 0.2-24.1). Estimated cancer specific survival rate at 5 and 10 years were 98.5% and 96.7%, respectively. Estimated survival rates free of distant metastasis at 5 and 10 years 97.5% and 95.1% respectively. Nine patients with localized RCC experienced local reccurence after NSS.Estimated survival rates free of local recurrence at 5 and 10 years were 98.3% and 95.7%, respectively. The long-term results of these series support the concept of organ sparing surgery for RCC in the presence of a normal opposite kidney with excellent long-term survival and a low tumor recurrence rate.