RAISON/GEMS is a PC-based software package, developed by Environment Canada, for the UNEP/WHO/WMO[UNESCO GEMS/Water quality monitoring programme, to support national and international water quality data handling and analysis activities. The Global Water Quality Monitoring Project (GEMS/WATER) was the first programme of its kind to address global issues of water quality through a network of monitoring stations in rivers, lakes, reservoirs and groundwaters on all continents. Through technical cooperation with developing countries, the programme has contributed to the establishment and expansion of national water quality monitoring systems in many countries. The objective of the expert review was to examine the utility of the RAISON/GEMS software package for the GEMS/WATER programme, not to examine the whole range of packages available. The basis of the review included: technical capabilities; compatibility with the global database; cost; degree of user-friendliness and ease of operation; long-term software support - e.g. continuing development activities at NWRI and the commitment of the Canadian Government; capability of the package to import maps from external 015 sources; production in different languages; and continuing development of the system beyond the present RAISON/GEMS package. The review of the software took the form of training/demonstrations combined with hands-on applications by the experts. Representatives from China and Mexico reviewed their experience with RAISON/GEMS.