This volume provides the proceedings of the First European Workshop on Parallel Processing Techniques for Simulation which was held at the end of October 1985. The Workshop was organized within the framework of a joint project sponsored by the Commission of the European Communities under the research part of the multiannua1 programme in the field of Data Processing aming at promoting collaborative research work in the Community. The project involved collaborative work between the Complex Systems Group of the Control Systems Centre at UMIST, the Systems Reliability Service of the United Kingdom Atomic Energy Authority and the University of Bergamo, Italy. The aim of this project was to develop decomposition coordination techniques which would be of help in the simulation of complex dynamical systems on parallel processing facilities. One of the major aims of the Workshop was to report on the results produced within the project and to try to relate these to the leading work going on in this field in other centres of excellence. With this in mind, the Proceedings Volume is split up into a number of parts corresponding to the main sessions within the Workshop programme.