This guidebook is written for environment protection inspectors and cus-toms officers in the Nordic countries to highlight the importance of controlling importation and sale of products that contain ozone depleting substances (ODSs), in particular CFCs and HCFCs. It describes the international restrictions as well as the EU and national regulations on this subject and gives some indications on how to plan control priorities and strategies. The expectations are that the guidebook should be used as a starting point for closer cooperation between the authorities involved ­ inspectors, customs officers, police and prosecutors at all levels ­ and lead to allocation of resources, collection of more experience and, eventually, also specialized enforcement campaigns. The guidebook is funded by the Nordic Council of Ministers and initiated by the Nordic Ozone Group, a cooperation between the officers in charge of ODS controls at the central environment protection agencies in the five Nordic countries.