Percutaneous tumor ablation has faced a major growth in recent years with progressive expansion of clinical indications and subsequent adoption by national and international guidelines. Such techniques have become popular due to their minimally invasive profile and precise image-guided targeting resulting into a significant decrease of the procedure-related morbidity. Traditionally, malignant, and to lesser extent benign tumors, have been treated with these new techniques in several different organs including liver, kidney, lung and bone. More recently, other anatomic districts/organs including thyroid, breast, uterus and soft tissues have also been treated. Nevertheless, in order to optimize clinical results, precise knowledge of physical principles underlying these new techniques is of paramount importance, since technical adjustments may be provided according to specific tissue features (e.g. vascularization, density, etc.) and clinical indications of the procedure. Therefore, the goal of this review article is to present all the available ablation techniques with particular regard to their underlying physical principles and most common clinical indications.