The paper discusses the use of modern information technologies, and in particular geographic information systems (GIS), in the management and control of major accident risk, For;this purpose, the regulatory framework of the recent "Seveso II" Directive is briefly described. This asks for more transparent procedures and decision-making, and requires consultation of the public in land-use and off-site emergency planning. Correspondingly, new demands are put to support tools being developed. The main features of tools dealing with hazard sources mapping, risk assessment, risk management, and emergency planning are discussed and examples are given. Moreover, it is argued that, if appropriately designed, their use can enhance the dialog between plant operators, authorities and the public to facilitate a consensus on risk issues. Finally, limitations in the use of these tools and prospects for future developments are discussed.