[1][2] Igartua emerged from the youth system at Athletic Bilbao alongside Javier Clemente, with both players establishing themselves in the first team at the age of 18 after making their La Liga debut in the same match, against Elche in September 1968.
[2][3] After scoring a spectacular and important goal in the Inter-Cities Fairs Cup against Eintracht Frankfurt,[3] Igartua started the 1969 Copa del Generalísimo Final, also against Elche, a 1–0 victory in Madrid.
[2][4] In October 1970, he suffered a broken leg in a match against Celta Vigo which kept him out of the game for seven months, and when he returned, he could not reach the same high levels of performance as before the injury and was no longer a first choice at Athletic;[2] he missed out on their 1973 Copa del Generalísimo Final success having featured in earlier rounds.
[2] In 1975 Igartua opted to move down to the second tier with Celta (managed by former Athletic goalkeeper Carmelo Cedrun and assisted by Pedrito, the man responsible for the broken leg five years earlier),[2] helping the Galicians win promotion in his first season, although they were relegated in the second.
He moved on again, returning to his native Basque Country with Deportivo Alavés, where he appeared regularly for four campaigns in the Segunda División before being forced to retire altogether aged 31 due to Spondylitis.