The term “diathermy” was coined in 1909 by a Berlin physician writing in Munchener Medizinische Wochenschrift, following the demonstration of a prototype apparatus at a medical congress in Budapest. The word is derived from the Greek word that means heating through.[2] The use of heat since Egyptian society and the use of caustic chemical since 16th century is known is surgical field.[1,2] However, the scientific foundations of electrosurgery were established in the late 19th century. During the 1890s, Nikola Tesla and Jacques-Arsene d’Arsonval investigated the medical applications of high-frequency electrical currents and demonstrated their relative safety in human tissues.[2] These discoveries led to therapeutic applications of high-frequency current for various medical conditions. Notably, John Marshall treated a patient with a right cheek fistula using a novel form of cautery that involved heating a platinum wire via electrical current.[2] A major breakthrough occurred between 1914 and 1927 when William T. Bovie demonstrated that high-frequency alternating current (250 kHz–2 MHz) could be used to incise tissue while simultaneously achieving hemostasis. This work culminated in the development of the first commercially viable electrosurgical unit at Harvard University. In 1926, Harvey Cushing introduced the device into the operating theatre and popularized its use in neurosurgery, employing it in over 500 neurosurgical procedures. Its success led to widespread adoption across multiple surgical specialties.[2] 1.Ramachandran, M., & Aronson, J. K. (2011). John Marshall's first description of surgical electrocautery. Journal of the Royal Society of Medicine, 104(9), 355–360. https://doi.org/10.1258/jrsm.2011.11k028 2.Salehinia, R, Nadiri, E (2022). History of The Cautery Device. Medical Journal of Islamic World Academy of Sciences, 2022;29(1): 25-29, doi: 10.5505/ias.2022.59244