He scored his first goal for Wisła in the Ekstraklasa Cup match against Górnik Zabrze on 28 November 2007.

Mączyński debuted in Ekstraklasa in the game versus Górnik Zabrze on 2 December 2007.

[4] On 15 November 2013, Mączyński made his debut for Poland national team in an international friendly against Slovakia, coming on as a substitute for Tomasz Jodłowiec in the 76th minute.

[5] On 14 October 2014, he scored for the first time in international competition in a Euro 2016 Qualifying game against Scotland in group D, giving Poland a 1–0 lead in the 11th minute.

This biographical article related to a Polish association football midfielder is a stub.