Scientists increasingly use Twitter for communication about science. The microblogging service has been heralded for its potential to foster public engagement with science; thus, measuring how engaging, that is dialogue-oriented, tweet content is, has become a relevant research object. Tweet content designed in an engaging, dialogue-oriented way is also supposed to link to user interaction (e.g. liking, retweeting). The present study analyzed content-related and functional indicators of engagement in scientists’ tweet content, applying content analysis to original tweets (n = 2884) of 212 communication scholars. Findings show that communication scholars tweet mostly about scientific topics, with, however, low levels of engagement. User interaction, nevertheless, correlated with content-related and functional indicators of engagement. The findings are discussed in light of their implications for public engagement with science.