Google Scholar Metrics’ launch in April 2012, a new bibliometric tool for the evaluation of scientific journals by means of citation counting, has ended with the duopoly exerted by the Web of Science and Scopus databases. This paper aims at comparing the coverage of these three databases and the similarity their journal rankings may have. We selected a sample of journals from the field of Communication Studies indexed in the three databases. Data was recollected on 1720 November, 2012. 277 journals were identified to which we calculated their hindex and ranked them according to such indicator. Then, we analyzed the correlation between the rankings generated. Google Scholar Metrics dobles the coverage of the other databases, reducing the bias toward English language both; web of Science and Scopus have. Google Scholar Metrics shows higher hindex values (an average 47% higher than Scopus and 40% higher than Web of Science), allowing to better rank journals. We conclude that Google Scholar Metrics is a tool capable of identifying the main journals in Communication Studies offering results as reliable and valid as the ones Web of Science and Scopus show.
