Within the framework of the Community research and training programme (Euratom) in the field of radiation protection, a probabilistic accident consequence assessment code, COSYMA, was developed in the late 1980s. The code enables estimates to be made of the health, environmental and economic impacts or risks of postulated accidental releases of radioactive material. Such estimates form an integral part of risk or safety analyses of nuclear installations and are increasingly being used as an input to regulatory considerations. The code is applicable for releases anywhere in Europe and incorporates state-of-the-art modelling in each module. A mainframe version of the code was made available in 1989 and distributed to a number of users. A Personal Computer version, PC COSYMA, has now been developed and is available to interested users, subject to an agreement between the Commission and the user. Some 50 copies have already been distributed since this version was made available in mid-1993. A small charge is made to cover the costs of distributing the code and providing the accompanying documentation and users guides.