Cancer is the second most common disease in the world. Due to its complexity, treatment is still not effective in many cases. Due to the various types of tumors and mutations that occur, it is very difficult to find standardized therapy. The use of electric fields is one of the newer methods in the treatment of tumors and is still a relatively unexplored but promising area. It improves the uptake of drugs into the cell, is used in gene therapy and in the ablation of tumor tissue. The therapy is very safe, the side effects are not pronounced and the recovery rate of the patients is very high. There are two main outcomes of the action of an electric field on a membrane. Irreversible and reversible electroporation. In irreversible electroporation, the structure of the membrane is permanently disrupted and it will not return to its original state, thus achieving cell death. With reversible electroporation, the membrane returns to its original state, and cell death does not occur. Electrochemotherapy is an improved way of delivering a drug to a tumor cell. The electric field increases the permeability of the membrane, and the drug enters the tumor cell more easily. With the application of electrochemotherapy, the need for doses of chemotherapy for treatment is reduced, the number of side effects is reduced, the treatment profile is improved. Bleomycin and cisplatin have been identified as drugs that could have improved electrochemotherapy. Studies with bleomycin have shown that it has a 50% improved effect when administered with electrochemotherapy, compared to self-administration. Gene therapy is a new approach to treating tumors. It can be used to correct a loss of function caused by a mutation or to express a deficient gene product at the physiological level.