ClinicalTrials.gov, the National Library of Medicine’s web-based registry of more than 46,000 clinical research studies, recently lauched a new interface. Although the old and new interfaces are currently running parallel, the old version will be permanently replaced within 2-4 weeks. The new interface significantly enhances functionality and navigation while preserving the core aspects of the site. New features include highlighted search terms, more display options, and additional capabilities for viewing studies and search results by topic. Improvements were also made to “Advanced search” and the display by location on the world map. Features of the new interface are fully described in the current issue of the NLM Technical Bulletin.