Radiofrequency (RF) ablation of primary or secondary malignant liver nodules under magnetic resonance (MR) guidance is technically feasible and may be clinically indicated in some situation where tumour conspicuity on ultrasonography (US) and computed tomography (CT) is inadequate for targeting and electrode placement. Although MR-compatible electrodes are now commercially available, MR-guided RF ablation requires implementation of a number of hardware and software modifications that are not included in all current diagnostic MR units. Hardware requirements include an in-room monitor and user interface, adequate surface coils, a RF generator with filtered frequencies and special connecting cables leading into the Faraday cage, and MR-compatible one-way material. Software packages should include dedicated rapid “fluoroscopic” 3D-sequences with T1- or T2-weighting and obtained in two orthogonal oblique planes, in order to allow near real-time visual feedback of the progression of the RF electrode(s) during the targeting procedure. With some experience, the procedure time may be limited to less than an hour. MR-based colour-coded mapping of temperature and energy deposition is technically feasible. However, it is hampered by the susceptibility artefacts generated by the RF electrode and by motion artefacts, and the clinical usefulness of this form of monitoring has yet to be proven. Signal loss on T2-weighted images and on contrast-enhanced T1-weighted images may be used to evaluate the ablation zone with MR imaging immediately after treatment. Clinical effectiveness of MR-guided RF ablation is similar to ablation performed under US or CT guidance.