Born in Paris, to a Jewish family, he studied to be a lawyer but was drawn to the motion picture business. He began his career when he co-directed the 1913 silent filmshortDe film... en aiguilles with André Heuzé. In addition to writing screenplays, during the period from 1916 to 1919, Diamant-Berger also published and edited a film magazine and books about the movies. In 1918, he was hired by Pathé and sent to the United States to help set up the company's film laboratory at Fort Lee, New Jersey. Upon his return to France, Pathé had him set up a laboratory in Vincennes, as well as organize a film studio in Boulogne-Billancourt.
Through his Barrymore connection, Diamant-Berger acquired the screen rights for a play produced on Broadway in 1921 written by John Barrymore's ex-wife, Blanche Oelrichs. His French language film version of the same title, Clair de lune (1932), starred Claude Dauphin and Blanche Montel. Among his notable sound films was a remake, Les Trois Mousquetaires (1932), a six-hour epic about the three musketeers for which he wrote the screen adaptation and used much of the same cast from his 1921 silent version. Diamant-Berger's other directorial efforts include two Arsène Lupin detective films in 1937.[1] However, after directing Tourbillon de Paris in 1939, he lost eight full years to World War II. In 1951, he directed the acclaimed drama Monsieur Fabre starring Pierre Fresnay.