Playing for the Polish national football team, he is most noted for having scored two goals against Soviet Union national football team on October 20, 1957 at Stadion Śląski. The rather small striker (163 cm, 59 kg) was capped 46 times and scored 27 goals.
In fact, he spent his entire career with Ruch, from 07/1939 to 06/1959, a tenure which included victory in the 1951 Polish Cup, and 3 Poland Master titles (1951, 1952, 1953). In total, he scored 177 goals for Ruch. He became the club's coach and scout in 1959, and having never cut ties with the team, is seen as a great example of loyalty within the Polish game.
His home region of Upper Silesia shares its history between Germany and Poland. In 2006, the documentary film „Das Alphabet von Gerard Cieślik“ was presented by „Antena Górnośląska“, as part of the exhibition „Oberschlesier in der deutschen und polnischen Fußballnationalmannschaft - gestern und heute. Sport und Politik in Oberschlesien im 20. Jahrhundert covering Upper Silesians which played for Polish national football team and/or German national football team.
In 2006, he also signed a protest against Roman Giertych.