The relevance of mobile working is steadily increasing. Based on new mobile devices (e.g. smartphones) and their innovative functionalities, an increasing amount of data is being made available ubiquitously. As a result, the growing diffusion of smartphones offers new potential for enterprises. Current mobile devices and related mobile networks have reached a high level of maturity. Thus, the organizational aspects of mobile work have become a focal point of interest for enterprises as well as for academics. This research article addresses the question: How does context influence the choice of communication channels of mobile knowledge workers? An explorative research approach is used to collect and analyse 418 communication incidents, which were initiated by mobile knowledge workers. The results indicate that (1) the context (e.g. travelling on trains) influences the usage of communication channels and (2) smartphones enable the usage of communication channels (e.g. email) in certain contexts.