"Shui wakashu" is the third imperial anthology of Japanese poetry after Kokin wakashu (Collection of Ancient and Modern Japanese poems) and Gosen wakashu (Later Collection of Japanese poems), and is the last one of the so called 'Sandai shu' (The Collections of Three Eras).
『拾遺和歌集』（しゅういわかしゅう）は、古今和歌集・後撰和歌集に次ぐ第三番目の勅撰和歌集で、いわゆる「三代集」の最後にあたる。