In organizational research employees' use of personal social media for work remains an understudied phenomenon. Yet, it is important to gain understanding of these online behaviors as they might have consequences on the individual and organizational level. We provide a typology for work-related Twitter use based on a large-scale content analysis (N = 38,124) of tweets sent by 433 employees across different organizations. We found that work-related topics were prevalent in 36.5% of all tweets. Employees’ work-related tweets paint a picture that is consistent with the archetypical social media behaviors - i.e., knowledge sharing and socialization - identified in earlier research. Employees share profession-, organization- and work-related tweets strategically with professional contacts, enhancing horizontal communication among organization members. Furthermore, Twitter enhances the integration of personal and professional life domains, as employees often tweet about their work outside regular work hours but also tweet on a personal title while at work.