K. A. Fedin’s diaries related to the time of the intense activity of the literary community “Serapion brothers” (1921–1924) have not been preserved. Therefore, the material for the studies of the life of the group as well as of its separate members is obtained by the researchers in the epistolary legacy of the writer. The researchers hardly ever refer to the diaries of the later period, apparently believing that Serapion brothers entirely disappeared from the literary life after 1929. However, the Serapion theme still figures on the pages of Fedin’s diaries of the 1948–1968. It is of interest how the already renowned master contemplates the artistic problems which concerned all the “brothers” at the dawn of their writing youth, “general” mentions of the Serapion brothers in the context of the current dwellings on literature and art. Nevertheless, in the diaries of the period in question, certain writers connected by their general past of the “brothers” come to the foreground. Among them, first of all, are Vs. Ivanov, N. Tikhonov, M. Zoshchenko, V. Kaverin, M. Slonimsky, N. Nikitin. Each of them is an object of Fedin’s scrutiny, who responded to all the personal and creative events in the life of the “brothers”. The article presents, among other sources, previously unpublished materials, which provide a means of identifying the role of Serapion brothers on the pages of Fedin’s diaries of 1946–1968. They make it possible to include these references in the context of how the relationships of the writers – the former members of the group – developed, and to determine the degree to which this literary phenomenon influenced Fedin’s life.