These Proceedings evolved from the OECD Co-operative Research Programme workshop on Potential ecological impact of transgenic plants expressing viral sequencies , held at the Agricultural Biotechnology Center in Godollo, Hungary on 24-26 April 1997. The OECD Co-operative Research Programme At the Directorate for Agrieulture of the Organisation for Economie Co-operation and Development (OECD) a co-operative research programme for Biological Resource Management has existed since 1990. It foeuses on work in four specific topie areas, one of whieh is Ecology and utilisation of new organisms (Theme 3). The activities promoted by this programme are post-doctoral fellowships (announced annually), and the organisation of expert workshops (1-2 workshops per Theme per year). The 26 OECD member countries participating in this programme are: Australia, Austria, Belgium, Canada, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, ltaly, Korea, Japan, the NetherIands, New Zealand, Norway, Poland, Portugal, Spain, Sweden, SwitzerIand, Turkey, the UK, and the USA.