The 2006 Turkish motorcycle Grand Prix was the third race of the 2006 Motorcycle Grand Prix season. It took place on the weekend of 28–30 April 2006, at the Istanbul Park circuit. The 250cc race saw a number of riders eliminated at the first corner.

This race was most notable for its thrilling ending, where Italian satellite Gresini Honda rider Marco Melandri overtook the Australian rookie Casey Stoner at the last corner, denying him his first ever win.

After two rounds, Loris Capirossi led the championship at this point, followed by the Repsol Honda riders Nicky Hayden with 36 and rookie Dani Pedrosa with 30 points. Valentino Rossi - last year's champion - only sat in fourth with a mere 27 points.

Chris Vermeulen took the pole position on Saturday - his first ever - followed by Nicky Hayden in second place and Sete Gibernau in third. Rossi only managed to qualify in a lowly eleventh position, and needed a strong result to stay in the title fight.

As the lights went out, Vermeulen kept his lead as the pack all took off with no problems or incidents. After about half a lap, Vermeulen still led, with Hayden losing two places and dropping to fourth. Gibernau moved up one place (third to second) and John Hopkins two (fifth to third), as did Casey Stoner (seventh to fifth). Melandri meanwhile recovered a whopping eight positions, with Valentino Rossi only making up one place (eleventh to tenth). During the opening lap, Gibernau overtook Vermeulen - making good use of the speed of the Ducati - and moved past to open up a small gap. However, at Turn 12, Vermeulen retook the lead from Gibernau, using the better cornering speed of his Suzuki to his advantage, to lead the race again going into lap two. Rossi also overtook the Kawasaki of Randy de Puniet for the ninth position.

By lap two, Gibernau overtook Vermeulen on the start/finish straight, with the other Suzuki of Hopkins following suit, relegating Vermeulen to third. Behind them, Stoner made quick work of Nicky Hayden and took fourth from him. Rossi meanwhile ran wide at Turn 7, making him drop back all the way to fourteenth after he made up a few places. At Turn 12, Hayden tried to overtake Stoner but ran wide, allowing Marco Melandri to overtake him in return and Stoner to swoop past both of them to reclaim fourth.

Lap three and Gibernau started to form a small gap to Hopkins, with Vermeulen still in third. Rossi overtook Makoto Tamada for thirteenth around halfway the third lap.

On lap four, Stoner shadowed Vermeulen's moves and overtook him at Turn 7 for third place. Vemeulen tried to fight back in acceleration, but by Turn 8 he was relegated to fourth, with Melandri ramping up the pressure as well after Melandri also took fifth from Hayden. Gibernau and Hopkins meanwhile opened up a significant gap to Stoner. Rossi meanwhile overtook Shinya Nakano for twelfth on the straight before Turn 9. Before Turn 12, Melandri overtook Vermeulen - who started to have tyre problems -, with Hayden following suit at Turn 14.