INTRODUCTION: There has been an increased incidence of small renal masses with a majority incidentally discovered in elderly patients or patients with several comorbidities. The historic role of renal biopsy has been limited due to initial concerns about accuracy and safety. This review analyses the current role of percutaneous renal biopsy. MATERIALS AND METHODS: A comprehensive literature review of PubMed and MEDLINE for reports of percutaneous needle core biopsy and ?ne needle aspiration of renal tumors that were published from 1977 to 2012. RESULTS: With the adoption of new biopsy techniques, there is a very low risk of tumor seeding. Symptomatic complications are relatively low; less than 2% require any form of intervention. The accuracy has dramatically improved over the past decade. While about 10%-15% of small renal mass biopsies are indeterminate, the rate of false negative renal biopsies is only 1% in contemporary series. Recent studies suggest that biopsy results can be improved by combining histological and molecular analysis. CONCLUSIONS: In contemporary series, renal mass biopsies (RMB) have a low complication rate and significantly improved accuracy. RMBs can better stratify patients into an active surveillance protocol and therefore potentially decrease the over treatment of small renal masses, especially in the elderly or patients with comorbidities.