The aim of this paper is to present the evaluations and results attained by our research group from the clinical applications of Electrochemical Therapy (EChT in short) on tumors, specifically of cats and dogs. Our in vivo results indicate that EChT is an effective cancer treatment. Application of EChT in human beings was approved by National Health Surveillance Agency, which is linked to the Brazilian Ministry of Health. To make EChT available for cancer patients in the Brazil, basic studies were conducted and a Phase I clinical trial was started.