The article provides a general examination of the two-volume “Diaries” of David Afanasyevich Tuaev (1902–1964), a major Ossetian playwright and author of a number of innovative plays, which were staged in hundreds of performances in the Ossetian drama theater. In the “Diaries”, which the author kept for twenty-four years (1940–1964), D.A. Tuaev appears in a completely new guise, corresponding to the poetics of the diary genre. He worked painstakingly and persistently on his plays, reworking them many times, and the “Diaries” represent a kind of stream of consciousness, a direct process of forming thoughts and images. These notes, as can be seen from the originals, he never edited – and even the inaccuracies here reveal a great personality, an open heart and a strong, natural artist. In the context of formal literary precedents and taking into account the latest research in the field of the diary genre, we characterize the “Diaries” from the point of view of their goal-setting and internal motivation, chronotope and composition, problematic and thematic content, language and style, and emotional and psychological background. The content of the “Diaries” is particularly notable in terms of the individual artistic experience of D.A. Tuaev, the creative history of his works and performances, the backstage of the Ossetian theater, the “shadow” side of Ossetian literary life and living, reliable portraits of Ossetian cultural figures of the Soviet era. These “Diaries”, like the diaries of many other great artists, due to their genre features are not examples of high art, but their cultural and methodological significance is indisputable; henceforth, no researcher of the history of the Ossetian theatre and the creative legacy of D.A. Tuaev will be able to do without them.