Objectives: Effective communication is critical to the safe delivery of care but is characterized by outdated technologies. Mobile technology has the potential to transform communication and teamwork but the evidence is currently uncertain. The objective of this systematic review was to summarize the quality and breadth of evidence for the impact of mobile technologies on communication and teamwork in hospitals. Materials and Methods: Electronic databases (MEDLINE, PsycINFO, EMBASE, CINAHL Plus, HMIC, Cochrane Library, and National Institute of Health Research Health Technology Assessment) were searched for English language publications reporting communication- or teamwork-related outcomes from mobile technologies in the hospital setting between 2007 and 2017. Results: We identified 38 publications originating from 30 studies. Only 11% were of high quality and none met best practice guidelines for mobile-technology-based trials. The studies reported a heterogenous range of quantitative, qualitative, and mixed-methods outcomes. There is a lack of high-quality evidence, but nonetheless mobile technology can lead to improvements in workflow, strengthen the quality and efficiency of communication, and enhance accessibility and interteam relationships. Discussion: This review describes the potential benefits that mobile technology can deliver and that mobile technology is ubiquitous among healthcare professionals. Crucially, it highlights the paucity of high-quality evidence for its effectiveness and identifies common barriers to widespread uptake. Limitations include the limited number of participants and a wide variability in methods and reported outcomes. Conclusion: Evidence suggests that mobile technology has the potential to significantly improve communication and teamwork in hospital provided key organizational, technological, and security challenges are tackled and better evidence delivered.