Rikardo Arregi Diaz de Heredia published his first book of poems Hari Hauskorrak (Fragile Threads) in 1993. He won the Critics Prize for that book. In 1998 he wrote Kartografia (Cartography), published by Alberdania, which also won the Critics Prize and was translated into Spanish as Cartografía in 2000. His poems can be found in various anthologies of Basque poetry published in other languages such as English (Six Basque Poets, Arc Publications, 2007). He has translated into Basque the Spanish poet Ernestina de Champourcin, the Portuguese poet Jorge de Sena and lately Jospeh Brodsky in 2022. He has worked on the collective book Desira desordenatuak. Queer irakurketak (euskal) literaturaz (Disorderly Desires: Queer Readings in (Basque) Literature), a study on gay issues in Basque literature. He was a member of the editorial board of the online literary magazine Volgako Batelariak.  His latest book of poems is Bitan esan beharra (It Must Be Said Twice), published in 2012, winner of the Spanish Critics Prize, translated to Spanish (Debe ecries dos veces, Salto de Página, 2013).