Background: Investigating usage and user activity, and identifying trends for The Cochrane Library are essential tools for providing high-quality, timely evidence for The Cochrane Collaboration. It assists in constructing a picture of how people use The Cochrane Library around the world, and allows us to identify the way in which reviews from The Cochrane Database of Systematic Reviews are accessed. Objectives: By looking at the 2009 full year and 2010 first quarter usage data for The Cochrane Library, it is possible to establish trends, usage patterns and user preferences surrounding The Cochrane Library and the databases within it. Methods: For the period of 1st January 2009 to 31st December 2009, plus the 1st January 2010 to 30 April 2010, the number of unique visits to www.thecochranelibrary.com, number of visits by country, and most accessed Cochrane reviews on Wiley InterScience were taken from the Wiley InterScience Data Warehouse, an analysis tool that stores and tracks usage data. Another set of usage data was obtained from all other licensed providers of The Cochrane Library, showing the number of abstracts and full text articles that were accessed during 2009 from Wiley InterScience, EBSCO, OVID, La Biblioteca Cochrane, BIREME and www.cochrane.org. Results: Data taken from all providers of The Cochrane Library show that during 2009: A search of The Cochrane Library took place every second; A Cochrane abstract was viewed every 2 seconds; A full text article was downloaded every 3 seconds. Conclusions: In summary, usage of The Cochrane Library in 2009 has increased considerably in comparison to 2008 and previous years. Over half the world’s population now have access to The Cochrane Library via one-click access (no login required), and it is clear that worldwide usage of The Cochrane Library is increasing as a consequence.