[en] Renal cell cancer is the most frequent malignant tumor of the kidney. Depending on tumor size, extension and general condition, radical or partial nephrectomy, which meanwhile can be performed laparoscopically, is still the therapy of choice. Patients with an increased surgical risk, or suffering from additional renal tumors or tumor in a single kidney, percutaneous tumor ablation is a helpful therapeutical option. Among all thermal ablation procedures, most experiences exist with radiofrequency ablation (RFA). A significant advantage of this technique is the possibility of direct puncture of the tumor without Seldinger technique and track ablation. This helps to reduce the risk of bleeding and tumor seeding within the puncture track. By use of modern ablation probes, lesions of up to 5 cm diameter can be created without repositioning of the probe. Initial superselective particle embolization is recommended in tumors beyond 3 cm in size, because renal cell cancer is often hypervascularized and devasularization helps to reduce ablation time. Furthermore, the tumor location within the kidney is influencing the ablation result. Exophytically growing lesions or tumors within the renal parenchyma can be treated with a safety margin. Tumors in a central location or with broad contact to the collecting system are no candidates for thermal ablation, because of an increased risk of thermal collateral damage. Computed tomography is an optimal imaging modality and crucial to planning, performing and controlling of a successful percutaneous RFA. Based on the previous experiences of 300 published cases, renal RFA results in an over 90% success rate associated with a low complication rate. A randomized controlled study comparing RFA and surgery is necessary to answer the question whether RFA can be considered therapy of first choice even for patients, who are according to the actual evidence surgical candidates. (orig.)