X-raying is arguably the most well-known, non-invasive technique for visualising the internal structures of ancient mummies and bog bodies. There are several factors such as the easy availability, the relative cheapness as well as the high spatial resolution, which speaks for this diagnostic modality in ancient mummy research. The aim of this short review is to address the advantages and pitfalls of this particular technique for such unique samples. We recommend that when results of X-ray examination of mummies are presented, the specific recording data should be listed, and any given finds, for example, of Paleopathology, should be cross-checked against other sources, for example, CT-scanning, direct inspection (also by endoscopy), and so forth.