Coached by Fernand Poirson, André Iuncker’s first major international podium finish came at the 1955 Mediterranean Games, when he won bronze as lightweight boxer. Shortly thereafter he moved into the featherweight division and captured several French national titles in that category, culminating in a gold medal at the 1959 Mediterranean Games. He was then selected to represent France at the 1960 Rome Olympics, where he was defeated in the first round by Ando Reddy of Ireland. He retired shortly after these Games and never turned professional. His brothers René and Marcel were also boxers and all three trained at the Gymnase Solvay.