At the Monitoring Workshop 2006 in Berlin the German Competent Authority 'BVL' presented a general concept for coordination and data handling in GMO monitoring by German authorities.  This paper will expand and detail the topic for coordinating the module 'Agro-Ecosystem / Agriculture'.  Initiated by the German Plant Protection Agencies in 1999, BBA coordinates a working group on monitoring genetically modified (GM) plants in the agro-ecosystem.  This working group may form a core for further coordination and harmonisation of GMO monitoring in relation to agriculture.  The working group provides a forum for stakeholders concerned with monitoring of GMOs as well as environment.  At present, GMO monitoring seems to suffer from inconsistent data acquisition techniques, restricted access to data, inconsistent formats, and unclear demands.  Evaluation of large scale effects of GM plant cultivation ? foreseen or unforeseen ? is a challenge to cover the broad scope of the European regulations.  Until now, neither applicants / breeders nor national or European authorities organised efficient means to handle and analyse the mass of heterogeneous GMO- or 'baseline'-related data to guide GMO monitoring regimes.  Facing these structural problems the working group should enable applicants, authorities and other stakeholders to address GMO-related concerns revealed in or arising from different monitoring sectors in the agro-ecosystem.  Networking between representatives of different GMO-related and non-GMO-related monitoring programs should allow to exchange experiences, establish 'task forces' / research groups and initiate concerted measures.