Background: The virtuality of teams has increased due to the emergence computer-mediated communication (CMC) tools in the last decades. The push of instant messengers (IM) in private life has also lead to a stronger influx in the professional context. Theories such as media-synchronicity theory or the computer-mediated communication interaction model have described the capabilities of CMC tools and indicated their usage in teamwork related contexts. In this realm, the transmission of social cues has always been a potentially important matter of discussion. Purpose: Relating to studies from Asia and research conducted at the beginning of the century, the impact of the use of IM as communication tools on knowledge sharing and teamwork performance in Germany shall be assessed. Method: A partial least square-structural equation model is developed and tested using a survey distributed via a snowball approach among professionals in Germany. Conclusion: The results show that there is a significant positive relationship between the use of IM and knowledge sharing, respectively teamwork performance through its influence on communication quality. However, there is also a negative impact on interactivity which negatively affects knowledge sharing. It is also indicated that interruptions do not seem to have a negative impact on teamwork performance as it was discussed and rejected in several previous studies. Emoticons as a transmitter of social cues have not demonstrated to be of significant importance for communication in a professional context as of now. IM use leads to a positive impact on the perception of communication quality. Overall, IM are on the way to become an important communication channel in teamwork tasks, but will mostly serve as a complementary means of communication.