The aim of this study is to examine the transposition and implementation of Article 12 of the Seveso II Directive, also known as COMAH (96/82/EC), in six EU Member States. Article 12 addresses the land-use planning issues associated with controlling major accident hazards involving dangerous substances. As the Directive should have been transposed by February 1999, the appropriate legislation should have been in place in order to enable this study to be undertaken. However, this proved not to be the case for every country. Experience in relation to both the transposition and implementation of Article 12 of the Seveso II Directive in the six case study countries has been variable. In three countries – Spain, Italy and England – Article 12 has been transposed virtually word for word into national legislation. In the other three countries, transposition has been undertaken differently: only a relatively minor amendment was made to existing German legislation, whereas in Denmark only the first paragraph of Article 12 has been transposed. Meanwhile, in the Netherlands the Article has not yet been transposed.