In the years 1923-1926 there was a female section in the club playing "tamburyna", a five-a-side game which consisted of hitting the ball over a suspended string.

In 1955, the then activist Adolf Schinohl, changed Górnik to "Górniczy Klub Sportowy Concordia Knurów" or "GKS" for short, a common abbreviation for mining clubs.

In the 1930s Concordia players were among the top teams this league, encountering hard-fought matches with Pogoń Katowice and AKS Chorzów.

In the autumn of 1946 Knurów competed with varying degrees of success in A-klasa, and a year later became vice-champion of Silesia, losing the decisive meeting with Ruch Chorzów (0:2 and 1:5).

Early in the 1950/1951 season, then as Górnik Knurów, for the first time in history, won promotion to the second division.

Playing in group D, they finished the first season in the second league in 3rd place, giving way to Wawel Kraków and Zagłębie Sosnowiec.

The meeting took place in Knurów, and they achieved a goalless drew with Gwardia, who were a newly relegated club from the top division at the time.

The club coached by Marcin Bochynek finished 11th, ahead of Broń Radom, Ursus Warsaw, Concordia Piotrków Trybunalski, Jagiellonia Białystok and Star Starachowice.

In the season 1986/1987 and 1987/1988 they finished in the second league twice in third place, which entitled them to perform in the play-off matches for promotion to the Ekstraklasa.

In the 1/8 final Górnik faced GKS Katowice and again after two goals by Krettek (2:1) advanced to the quarter-finals, where they were drawn against the aforementioned Wisła.

After the reorganization of the league, in a relegation play-off tie with Miedź Legnica, Górnik lost (1:2 and 1:0) and dropped to the third division.

The good times ended with the demise of the Polish People's Republic, in particular, after relegation from the second league.

After the promotion play-off defeat against Wisła Kraków, after which the players were accused of match-fixing, the attendances drastically fell.

In recent years, many crowds gathered at matches organised by Jerzy Dudek, where he started his career; for matches involving "Jerzy Dudek & friends" with players such as Milan Baroš, Vladimír Šmicer or Jacek Krzynówek taking part.

[10] A 27-year-old fan of Concordia, Dawid Dziedzic, was shot, and despite attempts to resuscitate him he died shortly in hospital hours later.

[17][18] The club has had a few famous players in its squad who played or coached in the Ekstraklasa and even in the national team, for most Concordia was where they started their professional careers: Arguably the most famous players are the Dudek brothers, Jerzy and Dariusz who hail from Knurów and started their careers at Concordia, and are considered local celebrities.

Rafał Krzyśka and Tomasz Dura are international Polish futsal players, who also started their careers at the club.