GOs are significant actors in conflict-related discourses and play a key role in the shaping of mediated conflict communication. Since previous scholarly work has rarely analyzed the way NGOs characterize the ‘reality’ of violent conflicts, this contribution to the special issue focuses on the publicity of NGOs in this field. On the basis of a big-data content analysis, the authors in particular investigate the epistemological status of NGOs’ strategic communication on war. They focus on ‘evidential claims’, the actual provision of evidence and the transparency of sources of evidential claims. The results are compared across different types of NGOs for their communication on six international armed conflicts. The findings suggest that the communication of NGOs in this is caught between their role of a strategic communicator and that of an expert. Improvement is especially needed concerning the indication of sources of evidential claims: 47 percent of all texts do not provide any source specification.