The US-based Committee to Protect Journalists condemned the murder of Abdel Karim al-Rubai, 40, who was the design editor for Al-Sabah newspaper.
He was shot by several gunmen on Saturday morning .
Joel Simon, the committee's executive director, said in a statement: "Al-Sabah and its staff have become repeated targets for insurgents. We urge the authorities to bring those responsible for this murder to justice."
Al-Sabah reported two weeks ago that it had received a death threat via e-mail against al-Rubai and his family signed by the military wing of the Mujahideen Council, an al Qaeda affiliate in Iraq, the committee said.
The committee said that 78 journalists, including al-Rubai, and 28 media support workers have been killed in Iraq since the war began in March 2003. The majority of victims have been Iraqis.