This single centre, retrospective study aims to determine whether performing a partial nephrectomy is oncologicallysafe for stage T3a renal cell carcinomas. Radical Nephrectomy is the gold standard surgical approach for T3a Renal Cell Carcinomas. However, a small but not insignificant number of patients pre-operativelystaged cT1/cT2 are treated with a partial nephrectomy but at final pathology are subsequently upstagedto pT3a.