The role of percutaneous biopsy to characterize large, locally advanced and metastatic primary renal tumors has not been well described. The goal of this article is to describe the potential advantages of biopsy for preoperative evaluation of patients with large renal tumors and advanced disease.Literature was reviewed for percutaneous biopsy and for locally advanced and metastatic renal tumors.Multiple studies have confirmed that percutaneous biopsy is safe, and the cost is minimal relative to the cost of surgical operation. Biopsy of large masses should obtain multiple core samples from several sites with tumors to decrease error from sampling heterogeneous tumors.Potential advantages of biopsy for large renal masses include identification of patients for retroperitoneal lymph node dissection who may have occult lymph node metastasis. In patients with metastatic renal cell carcinoma, biopsy characterizes tumors for patients who may not benefit from cytoreductive surgical operation. The role of biopsy is likely to expand in the future with the development of advanced molecular tools for risk stratification.