The title on the cover of the manuscript says "Murasaki Diary," but the diary does not contain the author's name, Murasaki Shikibu, so it is unknown since when it has been called "The Murasaki Shikibu Diary."
写本の表紙の表題は『紫日記』とあり、内容にも紫式部の名の記載ははなく、いつから『紫式部日記』とされたかは不明。