GMO Monitoring was made mandatory in the European Union. The according regulatory practice, however, is still under development. Recently, the European Food Safety Authority completed a guidance document which attempts to specify the requirements for general surveillance, i.e. the monitoring aspects that go beyond case-specific issues. While case-specific monitoring (CSM) follows relevant or unclear effects of a particular trait, as identified during risk assessment, general surveillance (GS) covers entirely unforeseen effects or those that are cross-functional and difficult to predict (indirect, delayed, or combinatory). Here, we outline an approach how to systemise monitoring issues, give examples for typical General Surveillance topics of oilseed rape and maize and then discuss the guidance how to setup GS monitoring plans.