He appeared in 225 La Liga matches over ten seasons, scoring a total of eight goals for Real Sociedad and Athletic Bilbao.

[1] Born in San Sebastián, Gipuzkoa, Imaz was immediately thrust into hometown club Real Sociedad's starting XI in La Liga at the age of 20 after a single season in the reserves.

[7] After helping the Lions to reach the group phase of the 1998–99 UEFA Champions League by netting in the 2–1 away loss against FC Dinamo Tbilisi (eventually qualifying via the away goals rule)[8][9] he played five times in that stage of the tournament, which ended in elimination in last place.

After 26 league matches over his first two seasons, Imaz was rarely selected after the arrival of manager Txetxu Rojo, meeting the same fate under Jupp Heynckes and retiring at only 30 due to injury problems.

[11] After retiring, Imaz engaged in politics, running as sports councillor for the Basque Nationalist Party in the town of Tolosa and being elected in 2003.