Nicky Hayden lead a Honda charge with the fastest time of the first day of practice in Turkey, with a 1'53''623 lap of Istanbul putting him at the head of a five-rider group of riders for the Japanese factory. Second position on the table was for Australian Casey Stoner, who suffered a late crash in the second session after heading the first, with Marco Melandri, Dani Pedrosa and Toni Elias. Colin Edwards came in sixth as the fastest non-Honda rider, with World Championship leader Loris Capirossi close behind. John Hopkins, Sete Gibernau and Makoto Tamada completed a top ten which was only split by eight tenths of a second.
Reining World Champion Valentino Rossi dropped to eleventh and went off the track during the session, whilst Australian Chris Vermeulen experienced another setback when his GSV-R had a technical problem in the final minutes.