The 7th Ministerial Environment for Europe Conference took place 20 years after the process “Environment for Europe“ was founded at the Dobříš Castle in the then Czechoslovakia in 1991. The process, evolving significantly over the years, now encompasses various elements of international environmental cooperation and is an important part of the UN Economic Commission´s for Europe environmental activities. The Czech Republic has been involved in shaping the process since its inception. Next to its other environmental focuses and the intense EU activities, transboundary environmental cooperation within UNECE has been its long-standing priority mirroring itself in the participation of experts and high-level officials in the various relevant UNECE bodies. The 7th Ministerial Conference was the first to take place after the reform of the process was negotiated in 2009, in which the Czech Republic played an important role. While analyzing the development of the last 20 years, the author concludes that one of the important factors shaping the policy within UNECE has been the pre-accession process of the Czech Republic and consequently the EU membership.