Throughout his career, Decorte only played for one team: Cercle Brugge.
He made his debut in the 1927–28 season, right after Cercle Brugge's national championship and cup final victory.
In Decorte's first match, Cercle lost 5–1 at the pitch of Beerschot.
Alphonse Decorte played his last match for Cercle against Daring Club de Bruxelles on 29 December 1935.
This biographical article related to association football in Belgium, about a forward, is a stub.