The inaugural season did not feature reigning F3000 champion Vitantonio Liuzzi, because the Italian was driving for Red Bull Racing in Formula One.
The series did feature two former F1 drivers, Italians Gianmaria Bruni and Giorgio Pantano, driving for Coloni and SuperNova respectively.
Nicolas Lapierre had taken his inaugural pole position but he was out before the race had started due to mechanical problems.
This was due to the event in the Imola sprint race, where Lapierre started with a fuel load with which he wouldn't have been able to finish, set a fastest lap and retired soon after.
Tactical errors caused them to lose the feature race, but Nico Rosberg gave them their first win at the sprint.
Rosberg went on to win the next two feature races, while Olivier Pla won both sprints having started from pole position in both of them.
Prémat also won the next race at Istanbul, while championship leading duo Kovalainen and Rosberg finished outside the points.
All of the teams used the Dallara GP2/05 chassis with Renault-badged 4.0 litre (244 cu in) naturally-aspirated Mecachrome V8 engines in 2005 in order to keep the field fair.
As this was the inaugural season in the series, car numbers were distributed by a pre-season session held at Circuit Paul Ricard on 6 April.