Guszalewicz studied singing at the Lemberg conservatory with Wysocki, and later with Gänsbacher in Vienna.
Guszalewicz made his debut in 1891 in Pressburg/Bratislava.
After Pressburg, he sang at the Stadttheater in Aachen, the Stadttheater in Brünn/Brno, and from 1896 to 1902 at the German Theater
in Prague.
In Prag, he sang the title role in the local premiere of Der arme Heinrich by Hans Pfitzner. and in 1901 took part in the world premiere
of Der polnische Jude by Karel Weis.
In 1896, he married his student, the soprano 
Alice Guszalewicz (1879–1940), who had a succesful career as a dramatic soprano and since 1905
was a member of the opera theater in Köln, where both lived.
From 1902, Eugen Guszalewicz was no longer a member of any opera houses and undertook guest appearances in and outside Germany:
Budapest (1895), Kroll-Oper Berlin (1892), Lemberg (1893, 1902), Frankfurt (1901),
Bern (1903). He sang up to his time of death.
Guszalewicz was at the beginning a lyrical tenor, but developed into a dramatic tenor singing Manrico, Raoul, Assad,
Otello, Tannhäuser, Canio, Manru, Éléazar, Ernani, ...
He recorded for Zonophone, including a duet with Alice Guszalewicz.
His daughter Genia Guszalewicz (1902–71) had, like her parents, a successful career.
Reference: Kutsch & Riemens
