A glance through the official gazette of most nations, developed and developing, will usually reveal the existence of phytosanitary legislation. Phytosanitary legislation serves several purposes, most importantly enabling countries to protect their agricultural resources and natural environment from the introduction or spread of pests. Phytosanitary legislation defines the institutional framework necessary for effective plant protection and improves the efficiency and effectiveness of national authorities toward this end. It also allows countries to implement their international obligations with a view to facilitating international trade in plants and plant products and fostering cooperation and research in the field of plant protection. A basic phytosanitary law sets out the government’s power to take action upon the appearance of a new pest, such as declaring a quarantine area and imposing restrictions on the movement of people, vehicles, plants and plant products into and out of the areas affected by the pest. It also covers inspections, imports and exports of plants and plant products and penalties for violations.3 Recent international developments have spurred many countries to re-examine their existing legal frameworks to better meet their international obligations and to improve the implementation of their phytosanitary activities. For example, the new revised text of the International Plant Protection Convention (IPPC) of 1997 incorporates a number of definitions and concepts that are generally not reflected in older national phytosanitary laws. Moreover, the phytosanitary standards prepared and issued under the IPPC have become essential for member countries of the World Trade Organization (WTO) through the Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement) of 1995. Even those countries that are not members of the WTO have found it useful to revise their phytosanitary legislation to meet the WTO and IPPC requirements, because in many cases their trading partners demand it. In such cases, the fact of having legislation which does not comply with the SPS Agreement can constitute a barrier to trade. It is in this context that FAO has increasingly been called upon to assist member countries in evaluating and updating their phytosanitary legislation. A government’s felt need to revise phytosanitary legislation may stem from internal or external forces, although the latter are increasingly important. Situations may arise which reveal weaknesses in a country’s existing administrative scheme for plant protection, while experiences in international trade may do the same. The opening up of regional and global markets is driving states to establish common rules that render the international exchange of goods simpler, and harmonization of phytosanitary legislation is an important step in that direction. These guidelines attempt to distil the experience gained and lessons learned during the implementation of FAO legal assistance activities in the phytosanitary field in recent years, carried out in close collaboration with the Plant Protection Division of FAO’s Agriculture Department. The guidelines discuss the many essential and desirable elements that should form part of modern national phytosanitary legal framework. They also identify the issues that ought to be considered by governments in reviewing their existing regulatory frameworks on plant protection, especially in light of the new revised text of the IPPC and the SPS Agreement.