Electrochemotherapy has grown out of simple cell experiments through preclinical studies to experimental clinical studies, to an accepted treatment modality for cutaneous metastases for any type of cancer. Electrochemotherapy has had a dynamic spread from few initial centers using custom-made electrodes to the current situation where standard operating procedures and clinically approved equipment are being used in many cancer centers. Treatment results have been remarkably consistent, possibly due to a robustness of the technology, and helped by the availability of clinically approved equipment and the early definition and adoption of standard operating procedures. Based on successful treatment of cutaneous metastases, a number of efforts have been initiated to expand treatment to tumors in internal organs. This requires development of specialized equipment, as well as clinical trials. The first of these trials are now published showing very promising results, and many further studies are ongoing. Finally a number of other avenues are being explored, including new drugs to be used, advanced use of imaging techniques, as well as combination with other treatments.