The main objective of this consultation was to review the scientific basis and procedures to establish effective post-release monitoring of genetically modified (GM) crops and develop guidelines to strengthen the capacities of member countries to design and carry out monitoring programmes. The major outputs of the meeting were: a review of scientific criteria and procedures that address the technical aspects of monitoring environmental effects of GM crops; two strategies that could be used as the basis for efficient monitoring programmes; and recommendations for scientists managing the monitoring process, policy and decision-makers, FAO and other relevant international agencies.