OBJECTIVE In the latest guidelines of the European Association of Urology, partial nephrectomy was a reference standard in tumors less than 7cm confined to the kidney. The invasion of the perirenal fat and therefore dissection in a potentially tumor tissue with an increased risk of recurrence. METHODS From 1995 to 2009, we retrospectively evaluated the oncological outcomes of partial versus radical nephrectomy in tumors with local extension beyond the boundaries of the kidney, without adrenal involvement or metastatic lymph node extension. We evaluated the histological factors influencing the prognostic. RESULTS A total of 43patients have been included (ten partial and 33radical nephrectomy). We did not found any significant difference in terms of specific and recurrence-free survival between partial and radical nephrectomy in tumor invading the perirenal fat (P=0.739 and P=0.683 respectively). Factors influencing the prognosis were the Fuhrman grade (P=0.010), the invasion of the urinary tract (P=0.017) and the presence of a positive surgical margin (P=0.041). The renal function was better after partial nephrectomy. The complication rate was similar between partial and radical nephrectomy. CONCLUSIONS The perirenal fat invasion by kidney tumor did not impact the oncological outcomes of partial versus radical nephrectomy with better functional outcomes for partial nephrectomy.