Sarrionandia studied the Basque language and earned a PhD in Basque Philology from the University of Deusto in Bilbao. He was a Basque language teacher and taught phonetics. His writings were published in a number of Basque magazines. He also translated books by Samuel Taylor Coleridge, Konstantino Kavafis, T. S. Eliot and Fernando Pessoa into the Basque language.