The mother and uncle of a boy named Jihad have expressed surprise that offence was taken after they sent him to school in a T-shirt emblazoned with 'I am a bomb'.
Young Jihad was sent to the kindergarten, in the southern town of Sorgues near Avignon, wearing the t-shirt on September 25.
The Sydney Morning Herald reported the boy's uncle bought him the T-shirt, which read "I am a bomb" on the front, and had "Jihad, born on September 11" on the back.
A teacher who saw the t-shirt reported it, and the town Mayor, Thierry Lagneau of the conservative UMP party, asked prosecutors to investigate a few days later.
"I condemn the attitude of the parents who shamefully took advantage of the person and the age of this child to convey a political message," Lagneau said.
The pair have now appeared in Avignon Court facing charges relating to condoning a crime by referencing the September 11 attacks.
In the hearing, the mother said she was "astonished" at the reaction to her son's top, and the coverage that it had received.
Official records show he was born on September 11, 2009, and was given Jihad as his first name.
The parents were not known Islamists, prosecutors said.
The judge postponed the trial until next year for technical reasons and set March 6 as the date for the next hearing. The accused made no comment to reporters as they left the courthouse.