In his Selected Poems, he has picked the best of his ten books of poems from four decades of his poetry. Louis Simpson has said, "Tillinghast's poems range confidently among different cultures. He has a sense of history as a living force." He has also published three nonfiction books, including Damaged Grandeur, a critical biography of Robert Lowell with whom he studied at Harvard, a book on Irish literature and culture, and a new book, Dirty August, a book of translations of the Turkish poet Edip Cansever that he co-translated with his daughter, Julia Clare Tillinghast.