Electroporation is a physical method for the delivery of various molecules into cells by application of controlled external electrical fields that transiently increase permeability of the cell membrane. This technique is now widely used as an alternative to viral gene delivery for transfection of therapeutic genes into different tissues. Gene electrotransfer holds great potential for clinical application due to the ease of preparation of large quantities of endotoxin-free plasmid DNA, the control and reproducibility of this method, and the development of electric pulse generators approved for clinical use. Electroporation has been utilized mainly for DNA vaccination against infectious diseases and cancer. It has also been used for the delivery of other therapeutic genes, mainly cytokines, used in the treatment of various diseases, including cancer, arthritis, multiple sclerosis and inflammation, following organ transplantation. Electroporation as a delivery system for chemotherapeutic drugs, termed antitumor electrochemotherapy, is already at the clinical stage and is being used routinely in several oncology centers in Europe. In addition, the first clinical trials for electrogene therapy of cancer are ongoing. Therefore, it can be presumed that electrotransfer of therapeutic genes into tissues will soon form a validated alternative to viral delivery systems in a clinical setting.