Background: Citation analysis can provide an insight into the publishing habits of the research community. Information is available not only on publishing authors and research groups, but also on those who are citing particular pieces of work. Objectives: This study will examine the citation Impact of the Cochrane Library, as observed through the lens of Thomson Reuter s Web of Science and Elsevier s Scopus. Methods: Publication and citation data will be downloaded from Web of Science and Scopus and analyzed to examine the differences and similarities between the groups of citing and cited authors, and between the journal metrics derived from these two data sources. Conclusions: New scales and ranking systems may provide a different picture of citation activity. Is this picture more or less indicative of the Impact of the Cochrane Library?