This book contains the course notes of the Summerschool on High Per- formance Com;~ting in Fluid Dynamics, held at the Delft University of Technology, June 24-28, 1996, under the auspices of and with support of ERCOFTAC (European Research Community on Flow, Turbulence and Combustion, WWW: http://imhefwww.epfl.ch/lmf/ERCOFTAC) and the J.M. Burgers Center (Graduate School for Fluid Dynamics, The Nether- lands, WWW: http://tnj.phys.tue.nl/fdl/Burgers.html). In addition to the material presented in the present volume, lectures were given by J. Hauser on "A parallel Newton-GMRES method for the 3D N avier-Stokes equations in complex geometries". The material written down by F.-S. Lien was presented by M.A. Leschziner. This book is addressed to students on a graduate level and researchers in industry engaged in scientific computing, who have little or no experience with high performance computing, but who want to learn more, and/or want to port their code to parallel platforms. Applications in computa- tional fluid dynamics are emphasized.