Trapero's film received 29 votes; Leonardo Favio's Aniceto, 19, and Daniel Burman's Empty Nest, 14
Leonera tells the story of Julia (Martina Gusman), a beautiful 25-year-old university student, who accidentally kills her lover. The pregnant woman, with no criminal record, is sent to jail, where she gives birth to a son.
Inspired by a real prison for convicted mothers who try to raise their prison-born children, Leonera was selected for official competition in Cannes this year and scored 130,000 admissions in Argentina.
Korea's Fine Cut is handling international sales for the film.
Argentina won its last nomination in 2002 with Juan Jose Campanella's Son of the Bride.
The local Academy, comprised of 250 renowned professionals (directors, producers, screenwriters, actors and technicians), also named veteran Leonardo Favio's musical Aniceto as the Argentinian submission for Best Latin American Film category at the Spanish Goya Awards to be held next January in Madrid.