The convoy belonging to the charity, widely known by its French acronym MSF (Medecins Sans Frontieres), was travelling yesterday from the southern town of Sibut to Grimari, about 100 kilometres away, when it was ambushed.
It was carrying non-medical material, including fuel, for MSF projects in the country's south east.
Thierry Dumont, the charity's chief in Central Africa, confirmed the death on state radio, adding that another MSF driver had been killed when his convoy came under attack in the north of the country on May 18.
"In all likelihood we will review how we work in this really dangerous region (where) the level of violence has increased," said Dumont.
Prime Minister Mathieu Simplice Sarandji will meet representatives of MSF to show solidarity with the group, according to Dumont and state radio.