This report provides an overview of spatial and land-use planning systems in OECD countries1 focusing on: (i) the governance systems across countries, (ii) the institutional and legal frameworks for spatial planning, and (iii) the various policy instruments used at different levels of territorial governance to articulate spatial development objectives, manage physical development and protect the environment. The report draws on available academic literature and policy documents. The analysis shows a strong relationship between governance models and authority and competences for spatial planning. Spatial plans at various spatial scales are used to create the preconditions for harmonising socio-economic development goals with environmental protection imperatives. Environmental assessment constitutes another key regulatory instrument. National plans, programmes, regional development and land-use plans as well as sector plans and policies are subjected to Strategic Environmental Assessment. Individual projects resulting from these policy instruments are subjected to Environmental Impact Assessment in most countries. In all countries, environmentally-related permits work together with environmental assessments to ensure that environmental considerations are taken into account in the siting of industrial installations and mega-infrastructure projects that would have significant impacts on the environment. The main challenges associated with environmental assessment in most countries include the political nature of the assessment process, the cost (time and money) of assessment particularly to businesses, limited consultation periods, limited technical capacity of institutions, the endeavour for independence and quality of the assessment and the absence of robust legislative frameworks.