During the battle of Warsaw in 1939 the Grand Theatre was bombed and almost completely ruined. Only the classicist façade survived the bombing. During the Warsaw Uprising of 1944 the Nazis shot civilians in the burnt-out ruins. The plaque to the right of the main entrance commemorates the suffering and heroism of the victims of fascism. In 1945 – 1965 the company performed on other stages while the theatre building was being restored and expanded according to designs by Bohdan Pniewski, under the supervision of Arnold Szyfman. The restored theatre was opened to the public on 19 November 1965. At that time it was one of the most imposing and best-equipped theatres in Europe, provided with state-of-the-art installations and equipment. The Polish National Opera in the Grand Theatre continues its 200-year tradition and produces works by Polish composers - from Karol Kurpiński, through Stanisław Moniuszko to Krzysztof Penderecki, but world classics are just as well represented; the company has in its repertoire the best operas by Beethoven, Bellini, Berg, Bizet, Borodin, Donizetti, Gounod, Massenet, Mozart, Offenbach, Prokofiev, Puccini, Rossini, Shostakovich, Richard Strauss, Tchaikovsky, Verdi and Wagner (including „The Ring”).

The Warsaw ballet company has worked with Adret, Alicia Alonso, Béjart, Butler, Cullberg, Lacotte, Lazzini, Lifar, van Manen, Massine Jr., Méndez, Messerer, Neumeier, Rodrigues, Sergeyev, Walter, Vinogradov, Yuriko and many Polish choreographers, such as Leon Woizikovsky, Stanisław Miszczyk, Witold Gruca, and Emil Wesołowski.

According to the plans of Antonio Corazzi, which were submitted for execution in 1825, the façade of the Grand Theatre was supposed to be decorated at the front with a triumphal sculpture of Apollo, patron of the arts, driving a chariot drawn by four horses. The outbreak and ultimate defeat of the November Uprising meant the idea was never carried out. At the order of the Russian field marshal, the idea to crown the building with the sculpture of this quadriga was abandoned, the aim being to deduct from the dignity of the national theatre's new seat. The ample pedestal at the top of the main façade of the Grand Theatre building remained empty for close to two centuries.