Here are some of his most notable works:
Poetry:
* The Barasoain Sonnets (1959) - a series of sonnets that celebrate the Philippine Revolution and the drafting of the First Philippine Republic.
* The Child of Sorrow (1958) - a collection of poems exploring themes of love, loss, and the search for meaning.
* The City of the Dead (1964) - a collection of poems reflecting on the nature of death and the human condition.
* The Corregidor Sonnets (1964) - a series of sonnets inspired by the historical events of World War II in the Philippines.
* The Elioth of the Sun (1957) - a long poem that narrates the story of the Filipino people.
* The Poetry of Ricaredo Demetillo (1978) - a comprehensive collection of his poetry.
Plays:
* The Madman of Manila (1962) - a satirical play that criticizes the political and social ills of the Philippines.
* The Woman Who Stole the Sun (1967) - a play based on Philippine mythology.
* The Daughters of the Sea (1970) - a play about the struggles of women in a patriarchal society.
Novels:
* The Adversary (1964) - a novel that explores themes of love, betrayal, and the search for identity.
* The God of the Hills (1975) - a novel about the relationship between humans and nature.
Literary Criticism:
* The Poetry of the Philippines (1954) - a critical study of Philippine poetry.
* The Philippine Short Story (1956) - a critical study of the Philippine short story.
* The Philippine Novel (1958) - a critical study of the Philippine novel.
Demetillo's works are characterized by their lyrical beauty, intellectual depth, and historical awareness. He is a master of language and his works have had a profound influence on Philippine literature.