A complete listing of the world's known plant species has long been considered desirable but has remained an elusive target for generations of botanists. The adoption of the Global Strategy for Plant Conservation has reinforced the urgent need for a global plant checklist to support, facilitate and monitor the conservation and sustainable use of plant diversity worldwide. The increasing availability of large databases of biological information over the Internet has demonstrated that many of the obstacles to the collation and dissemination of vast, shared datasets can be overcome. We examine the challenges that still remain to be addressed if the botanical community is to achieve its ambitious objective of delivering a working list of all known plant species by 2010.