Mitsuyoshi presided over Goryusai and Shikakusai (Nihongiryaku), removed Imperial Prince Tomohira's evil spirit that possessed FUJIWARA no Yorimichi by saying prayers with KAMO no Mitsuyoshi (Hobutsushu) and, advised FUJIWARA no Yorimichi as to the manners of coffining and how the funeral of Princess Kishi (or Yoshiko) should be carried out who had died giving birth to Imperial Prince Chikahito (Eiga monogatari).
五龍祭や四角祭を勤め（日本紀略）、藤原道に取り憑いた具平親王の悪霊を賀茂光栄と共に祈祷して取り除いたり（宝物集）、親仁親王出産の際に死去した皇妃嬉子の入棺・葬儀に関する方法を藤原頼道に勧申したり（栄花物語）している。