The series continued to use the Dallara GP2/05 chassis with Renault-badged 4.0-litre Mecachrome V8 engines, though technical improvements were introduced for the 2006 specification car. The rear wing adopted a biplane configuration, replacing the triplane design used in 2005 — which was retained solely for the Monaco event. The suspension uprights were reinforced front and rear, and Bridgestone supplied full-slick tyres for the first time, replacing the grooved slick specification of the inaugural year. The 2006 gearbox, manufactured by GearTek, included an eight-position barrel with software upgrades for improved gear selection.
The sole regulation change of note affected fastest lap points: a driver would now earn one point for the fastest lap rather than the two awarded in 2005, and had to start the race from their allocated grid position to be eligible.
Several high-profile drivers entered the series for the first time in 2006. Lewis Hamilton arrived from the Formula Three Euroseries championship, where he had won with ASM Formule 3, and joined ART Grand Prix. Timo Glock joined from Champ Car racing in North America, while Giorgio Pantano returned to the series after missing three early rounds.
Nelson Piquet Jr. won the opening race at Valencia, with rookie Hamilton finishing second alongside fellow newcomer Adrián Vallés. Hamilton's pace was immediately apparent, but he suffered an early setback at Imola, where he was black-flagged in the feature race for passing the safety car, forcing him to start the sprint race from the back of the grid. Gianmaria Bruni and Ernesto Viso shared the Imola victories.
At the Nürburgring, Hamilton won both races after Piquet suffered a heavy crash following a car failure. Hamilton's strong run continued through Monaco, where Nicolas Lapierre and Olivier Pla were injured and absent, and at Silverstone, where he won the feature and then pulled off an audacious sprint race overtake, passing Clivio Piccione and Piquet simultaneously in a single move.
Hamilton held a 26-point lead over Piquet heading into the Hungarian round. Piquet then delivered a perfect weekend at the Hungaroring, taking pole position, winning both races, and recording fastest laps in each, while Hamilton spun in qualifying and failed to score in the feature race. Piquet's resurgence continued in Turkey, where he won the feature race from pole. Hamilton responded well in the sprint, recovering from an early spin to finish second.
The championship was resolved at the final round in Monza. Piquet's pole position cut Hamilton's lead to eight points before the feature race, in which Giorgio Pantano beat both title contenders. In a remarkable postscript, Pantano was deemed to have ignored yellow flags on his fastest lap, stripping him of that point and awarding it instead to Hamilton — a development that clinched the title in Hamilton's favour before the sprint race had even started. Pantano won the sprint from eighth on the grid, completing a remarkable Monza weekend, with Hamilton second and Piquet further back.
The Valencia sprint race saw a significant accident when Adam Carroll rolled his car multiple times in a collision with Adrián Vallés. Both drivers escaped serious injury. At Barcelona, Hamilton was on course to win the feature race when he collided with his team-mate Alexandre Prémat on the final lap. Prémat won the race with Hamilton classified second.
Timo Glock's arrival mid-season proved influential. He moved from BCN Competición to iSport International between Monaco and Silverstone and immediately began winning races at Magny-Cours and Hockenheim, where he overtook José María López on the final lap.
Several drivers moved to Formula One directly from the 2006 GP2 season. Nico Rosberg, who had won the 2005 title, graduated to WilliamsF1. Scott Speed joined Scuderia Toro Rosso. Heikki Kovalainen became a Renault F1 test driver. Hamilton himself made his Formula One debut in 2007 with McLaren, going on to win the 2008 World Championship in his second season.
The championship comprised races at Valencia, Imola, the Nürburgring, Barcelona, Monaco, Silverstone, Magny-Cours, the Hungaroring, Istanbul Park, Hockenheimring, and Monza. The planned Spa-Francorchamps round was cancelled after local authorities began major circuit repairs. The season ran from 8 April to 10 September 2006.