Mungiu's devastating film about two women sharing the drama of a back-alley abortion and the daily despair of life under communism, won Cannes' coveted Palme d'Or on Sunday.
"President Traian Basescu has signed a decree to bestow the National Order of the Star of Romania to director Cristian Mungiu for his contribution to promoting Romanian cinema around the world," the presidency said.
Basescu also decided to honor deceased filmmaker Cristian Nemescu whose film "California dreamin'" won the festival's sidebar section Un Certain Regard, focusing on new upcoming directorial talent.
Nemescu, who died in a car accident last year aged 27 before completing the film, will receive the National Order of Merit award.
With only 10 to 15 films produced annually, Romania's new generation of film-makers, trained at the country's sole film school, are relative newcomers to the European movie scene.
But film festivals have been paying increasing attention in recent years to the eastern European country's young directors.