This article examines how Norwegian and UK health authorities used social media, and especially Twitter, during the 2014-15 Ebola outbreak. The microblogging service has been regarded as a promising medium for crisis communicators due to its immediacy and dialogical potential. Twitter allows communicators to respond directly to users’ concerns and provide them with more precisely tailored information. However, scholars have raised questions over organizations’ ability to respond to the the medium. We address these questions in two ways: 1. we examine the social media strategies adopted by the health authorities at the time of the outbreak. 2. we conduct an analysis of tweets produced by health authorities concerning the Ebola outbreak. Our analyses display some differences between UK and Norwegian authorities in terms of the strategies they adopted and the tweets they produced. However, neither country fully exploited Twitter’s dialogical potential. Both countries authorities preferred a vertically integrated approach with minimal opportunities for the public to engage and little monitoring of the wider Twitter ‘conversations’. We conclude that the emergence of social media has not led to a paradigm shift in crisis communication for these countries’ health authorities, rather to an evolution and adaption of practices and policies.