Sponsored by the Dalton Division of the Royal Society of Chemistry, the fourth International Conference on the Chemistry of the Platinum Group Metals was held at the University of Cambridge on 9th to 13th July 1990. Previous meetings in this series have been held in Bristol (1981), Edinburgh (1984) and Sheffield (1987). More than three hundred delegates, over one third from overseas, attended the meeting for a programme of twenty-seven lectures and almost two hundred poster presentations.