Considered one of the most important Italian artists of the 20th century, De Filippo was the author of many theatrical dramas staged and directed by himself first and later awarded and played outside Italy.

[2] He and his siblings Annunziata "Titina" and Giuseppe "Peppino" were extramarital because Scarpetta was actually married since 1876 to Rosa De Filippo,[3] Luisa's paternal aunt.

[6] In 1925, the company played in Milan's Teatro Fossati where Eduardo di Filippo was spotted and then praised in a review by Renato Simoni, then the most influential critic of Italy.

[6] In 1931, Eduardo formed a theatre company with his brother playwright Peppino and sister Titina, called Compagnia del Teatro Umoristico I De Filippo.

In 1931–32 the company toured Italy, then they returned to Naples and staged for Teatro Nuovo such plays as Farmacia di turno (The On-Duty Farmacy), Tutti insieme canteremo (We’ll All Sing Together), Miseria Bella (Splendid Poverty).

Soon Pirandello give Eduardo the right to adapt Liolà, the play with Peppino in the title role had great success.

[10] The protagonists of Eduardo's plays were usually misfortuned, traumatized, and scorned by the closest relatives and friends, but remained full of virtue and human dignity.

[11][12] In the late 1930s and early 1940s, raising sympathies for Fascism in society made the company’s work much harder: their performances were often interrupted and the brothers received multiple threats.

In 1973, Franco Zeffirelli's production of De Filippo's 1959 play Sabato, domenica e lunedi (translated as Saturday, Sunday, Monday), starring Joan Plowright, Frank Finlay, and Laurence Olivier, was presented at London's National Theatre and won the London drama critics' award.

De Filippo was praised for his poetic approach and unique way of showing drama through comedy; for breaking the limits of a dialect and opening Neapolitan culture to the world.

[19] In 1981, for ‘highest achievements in the arts of theatre and literature’, he was named senatore a vita by the President of the Italian Republic Sandro Pertini.

[18] De Filippo was the one to discover the talent of Marina Confalone, in his theatre company she thrived into one of the best Italian actresses of her time.