She married the novelist Alberto Moravia in 1941, and through him she met many of the leading Italian thinkers and writers of the day.
Towards the end of World War II, Morante with her husband, novelist and film critic Alberto Moravia, fearful because both were half Jewish, fled to the area around the Ciociara region near Rome, a flight that inspired Morante's "La storia" and Moravia's "La Ciociara" (translated into English as "Two Women" and later made into a film with Sofia Loren). Southern Italy is the backdrop for much of her work. She began translating Katherine Mansfield during this period, as well as working on her first novel—she even risked returning to war-torn Rome to retrieve the manuscript of "Menzogna e sortilegio" and obtain winter clothes.
Following the war, Morante and Moravia met American translator William Weaver, who helped them to find an American audience. Her first novel, 1948's Menzogna e sortilegio, won the prestigious Viareggio Prize, and was later published in the United States as House of Liars in 1951. However, Morante and others found the English translation quite poorly done, to Morante's great disappointment.
Morante and Moravia separated in 1961, and Morante continued to write sporadically. La storia (History), a story about Rome during World War II, appeared in 1974, which although a bestseller in Italy for the publishing house Einaudi, issued in an economical paperback edition at Morante's request, provoked a furious and at times negative reaction from literary critics on the left, who disliked its anti-ideological polemic. After her friend Pasolini wrote a negative review of the book, she broke off their friendship.