A general description of the Notaty codzienne (a diary) of T. Banachiewicz (1882–1954) is given. Also a list of contemporary papers using information as contained in the Notaty codzienne is presented. At the end of the article some original fragments of the Notaty codzienne are quoted: 1. A short narration on the – so called – Sonderaktion Krakau (the arrest and a transfer of Cracow scientists to the Sachsenhausen concentration camp by the Nazi troops in November 1939). 2. A choice of some short funny stories and anecdotic notes.