Geiger grew up in the village of Wolfurt near Bregenz. He studied German studies, ancient history and comparative literature at the universities of Innsbruck and Vienna. He has worked as a freelance writer since 1993. From 1986 to 2002, he also worked as a technician at the annual Bregenzer Festspiele summer opera festival.
In 1996 and in 2004, he took part in the Ingeborg-Bachmann-Preis competition at Klagenfurt.
In October 2005, he was the recipient of the first Deutscher Buchpreis[1] literature prize (awarded by the booksellers' association of Germany) for his novel Es geht uns gut.
Geiger lives in Wolfurt and Vienna.