One of the most importants acts by the club was the building of a stadium on Tratinska cesta (today's Stadion u Kranjčevićevoj), then the biggest in Zagreb.

The Yugoslavia national football team played eleven matches at the club's grounds.

[1] Apart from football, the club also competed in athletics, skiing, field hockey and table tennis.

The club's most famous footballers were: Pavelić, Babić, Ivan Belošević, Jazbec, Monsider, Pavletić, Aleksandar Živković, Kodrnja and Karlo Muradori.

NK Zagreb's third jersey is green in honour of Concordia, whose old stadium is now their own.