We performed computed tomographic (CT)-guided percutaneous needle biopsy for renal tumors that were difficult to diagnose or were inoperable malignant renal tumors. Nineteen patients who underwent CT-guided percutaneous needle biopsy between November 2007 and March 2015 at Hamamatsu University Hospital were included in this study. The median tumor diameter was 78 mm (40-140 mm). Seventeen patients were diagnosed pathologically by biopsy, but 2 patients could not be diagnosed despite the existence of adequate sample volume. One patient had an adverse complication ; fever (CTCAE ver 4.0 grade 1). The median duration of follow-up was 21 months (0-111 months), no one had tumor seeding along a needle tract. CT-guided percutaneous needle biopsy of renal tumors is helpful for pathological diagnosis and further treatment planning. However, there are still some limitations to obtain an accurate diagnosis.