This text proposes an analysis of wartime diaries using a concept whereby diary is approached on a broader basis than just as a text, namely, as a writing praxis of one's everyday life, having three essential dimensions to it: existential-pragmatic, material, and textual. In all those dimensions, war exerts a critical impact on what shape the practice of keeping a diary takes. The existential-pragmatic facet primarily includes the various motivations for one to write down his or her diary (be it existential, social, historical, or pragmatic). Whilst being testimonies to the times of violence, killing, and annihilation, wartime diaries simultaneously become existential acts keeping up the space of what is human, in the face of the inhuman. Seen from the material angle, wartime diaries disclose their specificity both as regards their carriers (such as using some utilitarian 'carriers' of the printed word, such as pieces of packaging, labels, forms) and their look or physical shape (mutilations, gaps, destroyed or lost diaries). The textual dimension of wartime diaries is only mentioned in this article, as part of polemic with Jacek Leociak's book titled 'Tekst wobec Zaglady'. In the final section, the author indicates the way in which a contact or clash occurs, in all the three dimensions of wartime diaries (i.e. pragmatics, text, and diary's materiality), between the common and the uncommon, the everyday and the unusual, the ordinary and the extraordinary, the human and the inhuman. This particular trait is treated as the decisive one in terms of wartime diary's singularity against the textual cultural world's space.