Background Twitter is one of the fastest growing social media networks for communication between users via short messages. Technology proficient physicians have demonstrated enthusiasm in adopting social media for their work.

Objective To identify and create the largest directory of emergency physicians on Twitter, analyse their user accounts and reveal details behind their connections.

Methods Several web search tools were used to identify emergency physicians on Twitter with biographies completely or partially written in English. NodeXL software was used to calculate emergency physicians' Twitter network metrics and create visualisation graphs.

Results The authors found 672 Twitter accounts of self-identified emergency physicians. Protected accounts were excluded from the study, leaving 632 for further analysis. Most emergency physicians were located in USA (55.4%), had created their accounts in 2009 (43.4%), used their full personal name (77.5%) and provided a custom profile picture (92.2%). Based on at least one published tweet in the last 15 days, there were 345 (54.6%) active users on 31 December 2011. Active users mostly used mobile devices based on the Apple operating system to publish tweets (69.2%). Visualisation of emergency physicians' Twitter network revealed many users with no connections with their colleagues, and a small group of most influential users who were highly interconnected.

Conclusions Only a small proportion of registered emergency physicians use Twitter. Among them exists a smaller inner network of emergency physicians with strong social bonds that is using Twitter's full potentials for professional development.