It was his performance in Molière's Tartuffe of the Burgtheater 1899/1900 season, which stunned the renowned Austrian actor Josef Kainz, playing the lead role.

The following year took him to the New German Theatre in Prague and in 1903 he joined the ensemble of the Deutsches Theater in Berlin, where he became a protégé of the influential director Max Reinhardt.

[4] Together with Rudolph Schildkraut he performed in Reinhardt's staging of Shakespeare's The Merchant of Venice, now emphasizing his melodious speech, which despite first damning reviews finally made him a star.

Moissi and the Reinhardt ensemble toured Russia in 1911 and was acclaimed in Saint Petersburg by critic and dramatist Anatoly Lunacharsky for his interpretation of Sophocles' Oedipus.

In 1920, he played the leading part in the first performance of Hugo von Hofmannsthal's Jedermann adaption of The Somonyng of Everyman at the Salzburg Festival.

In his honor, the drama school of the Academy of Music and Arts in Tirana as well as the university and the city theatre of Durrës were named "Aleksandër Moisiu".