Xabi Prieto started his career as a football player in his hometown of Basque traditional club Real Sociedad. His professional debut was in season 2003/04. The midfielder quickly rose to the strain force. In his inaugural season he scored two goals in eleven games. The following year he was already running at 23 times. His breakthrough came in 2005/ 06 when he scored nine goals in 38 games. This season, he came in every game for use.
Despite the decline in 2006/ 07 Xabi Prieto stayed with his hometown club. Prieto reached San Sebastian but again the rise in the 2009/10 season and played ever since in the Primera Division.