The Third Joint Varenna-Grenoble International Symposium on Heating in Toroidal Plasmas was held at Grenoble, France, from March 22 to 26, 1982. Previous Symposia were held in 1978 at Grenoble, France, and in 1980 at Como, Italy. These meetings are jointly organized by the Commissariat à l'Energie Atomique (France) and the International School for Plasma Physics (Italy). The application of supplementary heating in toroidal devices is of growing interest and there were almost 200 participants at the Symposium.