The goal of the GAMM-Committee for Numerical Methods in Fluid Mechanics (GAMM- Fachausschuf3 fUr Numerische Methoden in der Stromungsmechanik) is to bring together European research workers from different fields who are working on fluid mechanica I problems and develope and use Numerical Methods as mathematical tools, and to foster communication and cooperation between these people and the mathematicians working on the theory of Numerical Methods. The GAMM-Conference on Numerical Methods in Fluid Mechanics, which supplements the other activities of the committee, e. g. the GAMM-Workshops, is held every second year. The Third GAMM-Conference on Numerical Methods in Fluid Mechanics was held at the DFVLR, Koln, October 10 to 12, 1979. Approximately 100 scientists from 13 European countries attended the conference. In 32 papers problems were treated rang- ing from basic numerical questions to the application of Numerical Methods to basic fluid mechanical problems in Aerodynamics, Atmospheric Research, Nuclear Energy Techniques, Solar Energy Research, Turbomachines and Cascades. In two presentations the results of the GAMM-Workshops "Finite Element and Finite Volume Methods for Transonic Flow" (Chairmen W. Schmidt and F.G. Sator), and "Computation of Inviscid Transonic Flow" (Chairmen A. Rizzi and H. Viviand) were discussed. The report on the latter workshop will appear in "Notes on Nurnerical Fluid Mechanics" of Vieweg, too.