In this chapter critical discussion is provided on the recent innovations and the potential of the Electro-Fenton (EF) and EF-related processes as eco-engineered technologies in the field of water treatment. Emphasis is placed on the treatment of water and wastewater to eliminate a wide variety of synthetic organic pollutants, such as pesticides, pharmaceuticals, and dyes, the refractory nature of which requires the application of strong oxidants for their total elimination. In comparison to the general public acceptance of traditional and/or advanced water treatment technologies (e.g., activated carbon, membrane technologies, etc.), there is ambiguity or skepticism regarding EF adaptation. This is due to the lack of technology certification, the limited large-scale applications, or even the small number of demonstrations in realistic operational environments. In view of this state of technology, the parameters involved in designing and operating EF systems are discussed together with the appropriate engineering rules that can support optimal system design and operation so that these systems can be used at an efficient, effective, and profitable manner at industrial scale.