The major contribution of electrical engineer, scientist and inventor Nikola Tesla (Smiljan, Croatia, 1856 – New York, USA, 1943) to medicine was his high-frequency, high-voltage transformer known as the Tesla coil. High frequency currents are used in diathermy, as they, passing through the body, transform electrical energy into a therapeutic heat. Tesla himself spoke about this effect in an 1891 issue of Electrical World, reporting on an experiment in which he passed current through his own body. Even though he did not have medical training, he was interested in physiological effects of electricity and kept correspondence on electrotherapy with J. Dugan and S. H. Mahonell. In a 1896 issue of the Electrical Review Tesla published skull X-ray shots, beating Roentgen to it. Six years later he observed that placing an object before a photographic plate exposed to a high-frequency electrical field resulted in an image of the object surrounded by light. This phenomenon was later termed the Kirlian effect, and it refers to the aura, that is, the energy field produced by all living organisms. Tesla also designed an oscillator to relieve fatigue of the leg muscles. He experimented not only with the physiological effects of mechanical vibrations, but also with electrical narcosis. This review starts from museum materials, exhibits and literature, and continues with Tesla’s biography, focusing on inventions that found application in medicine. It concludes with a brief description of the Tesla coil built in 1908 and kept at the Department of Physics of the Rijeka University Medical School. By inventing the coil and discovering the X-rays, Tesla made a significant contribution to medical diagnostics and therapy. In the last part of this paper the authors summarize other Tesla’s inventions which are not well known but are also interesting for medicine such as an ozone generator. Tesla patented his first ozone generator in 1896, and in 1900, he formed the Tesla Ozone Company. Tesla sold ozone machines to doctors for medical use. With inventions which are summarised and presented in this paper, Nikola Tesla gave a very important contribution to medicine althought medicine was not his main field of research.