Formed in Real Sociedad's youth system, he made his senior debut with the B team in Segunda División B.

On 2 March 2005 he played his first La Liga game, coming on as a substitute for Óscar de Paula in the 87th minute of a 2–1 home win against Real Zaragoza.

[1] Domínguez spent the following two seasons on loan, with SD Eibar (Segunda División) and Real Unión (third tier), both in the Basque Country.

In the summer of 2007, his contract expired and the free agent signed with UE Lleida in division three, only managing to score twice during the campaign.

[6] Domínguez returned to Real Unión for a third spell on 4 July 2012,[7] going on to see out his career with the club in the third division and being immediately appointed its manager on 19 May 2018.