Regulatory frameworks are the mechanisms to ensure that both genetically modified (GM) crops, which are to be released into the environment, and GM foods and feeds, which need to be approved before consumption, are evaluated from both environmental and human health viewpoints. Regulatory committees, comprising independent experts, carefully examine the detailed dossiers of information that accompany the applications and also review the current relevant scientific background information in coming to their decisions. This paper explains the work of two key GM advisory committees and describes progressive developmental regulatory changes, which have followed incremental increases in science knowledge, and have also been influenced by the needs of the society they serve. The paper does not attempt to detail the specific assessment stages of the processes ? these are described adequately elsewhere and for those the reader is referred to committee annual reports or websites.