This paper explained and discussed the concept of forest certification, a process of verification that forest management has been carried out according to a set of accepted principles. The requirements for an effective and efficient certification programmes include acceptability to stakeholders, a contribution to sustainable management and minimisation of trade distortions. These requirements provide a basis for a detailed comparison between the two main approaches to certification, the most important difference being that the Forest Stewardship Council's system uses performance criteria while the International Organisation for Standardisation prefers management criteria. The author concluded by identifying the most pertinent questions for future research.