The French foreign ministry on Saturday said George Malbrunot of Le Figaro and Christian Chesnot of Radio France International have not reported on their location for more than two days.
"The French embassy is completely mobilized but their search has not produced any results for the moment," the ministry spokesman said.
The two journalists often worked together and published a book on Iraq last year.
It is not clear if the two journalists were reporting from Najaf where US forces have battled Shia leader Muqtada al Sadr's al-Mahdi Army.
Italy's foreign ministry, meanwhile said, a freelance Italian journalist who had been working in Najaf was also missing.