Percutaneous biopsy has long been used to diagnose malignancies of the kidney. It is an established technique with multiple indications. Percutaneous biopsy now can be used to diagnose benign conditions that may mimic a malignancy and lead to unnecessary treatments. Advances in cytological techniques such as immunocytochemistry and cytogenetics have allowed for an increased diagnostic yield. In this review, various benign entities that may present as a renal mass are discussed and the vital role of percutaneous biopsy detailed.