This publication provides guidelines for all FAO units (headquarters departments and offices, as well as decentralised offices) to undertake environmental impact assessments (EIA) of field projects. EIA is a tool for decision-makers to identify potential environmental impacts of proposed projects, to evaluate alternative approaches, and to design and incorporate appropriate prevention, mitigation, management and monitoring measures. Environmental impact assessment cannot be divorced from social impact of the project, and examples such as land tenure and rights, rural livelihoods, and traditional practices are considered as a key dimension of the EIA process.