Radiofrequency ablation (RFA) of primary and secondary liver malignancies is a promising and rapidly evolving technique, which increasingly gains importance, A new field of RFA is the minimal invasive therapy of osseous and soft tissue tumors. In the management of osteoid-osteoma, RFA is a well established treatment option. Basic principles, indications, complications and results of RFA will be presented. A careful evaluation of indications for RFA in osseous or soft tissue neoplasms is mandatory. In patients who are neither candidates for surgical tumor resection nor respond to chemotherapy, there is a need for alternative treatment options. In these preselected patients a substantial improvement in quality of life with low associated morbidity can be provided by RFA. In malignancies of bone and soft-tissue tumors, RFA is a palliative treatment option. Therefore,the results can not be compared to those of surgical resection or chemotherapy which essentially are employed with curative intention. Our own experiences as well as data published in the literature indicate that RFA is a helpful tool in preserving patient's quality of life. The high technical and clinical success together with a low complication rate makes RFA of osseous and soft tissue neoplasms a valuable supportive tool for patients not referable for surgery or systemic therapy.