The court found Jacques Langevin, Christian Martinez and Fabrice Chassery not guilty of breaching France's strict privacy laws when they photographed the pair inside their limousine in 1997.
Martinez of the Angeli agency, and Chassery and Langevin who worked at the time for the Sygma agency, were put on trial following a complaint by Dodi's father, Egyptian millionaire Muhammad al-Fayed.
Diana, Dodi and driver Henri Paul died in a high-speed crash in a tunnel on 31 August 1997, as their Mercedes was pursued by paparazzi on motorbikes through central Paris.
Following the court decision, al-Fayed rushed to show he is not willing to give up. The London-based tycoon told reporters he was launching an "immediate appeal".
In a statement, al-Fayed said he failed to understand the logic behind a French judge's decision not to convict the photographers and give them suspended sentences, as recommended by the prosecution.
Photojournalist Jacques Langevin
speaks to the media in Paris
"The paparazzi played a significant part in the tragedy and they should be punished," he said in the statement, written on the letterhead of his Harrods department store. "Accordingly I have lodged an immediate appeal."
Al-Fayed, lodged the complaint that triggered the trial. It hinged on a precedent in France that the interior of a car is deemed private, even on a public road.
Breach of France's privacy laws can in theory be punished by
a year in jail and fines of up to 45,000 euros ($53,550).
Al-Fayed lost a bid to have photographers chasing the car tried for manslaughter when France's highest court ruled they were too far away to have caused the accident.
Evidence at the initial inquiry showed the driver had been
drunk at the time of the accident, something rejected by his