This study examined the use of Twitter for online discussions in one asynchronous online, journalism class. A content analysis of the transcripts of the tweets from 25 undergraduate students was performed, coding for social presence using the social presence density measurement tool, one of the three aspects of the community of inquiry framework. Participants generated 1096 unique tweets over a 12-week course. Additionally, the community of inquiry survey was administered at the end of the course. Internal consistency measures and correlation analysis were used to identify the relationships between the social presence density scores and the community of inquiry survey results, which showed significant positive relationships exist between teaching, cognitive, and social presence, and the nature of the tweets. Results also underscored that social presence could be established on a micro-blogging platform, making it a potentially useful tool in an online learning environment.