During his club career he played for Wacker Wien.

Kollmann earned 16 caps for the Austria national football team, and participated in the 1954 FIFA World Cup and the 1958 FIFA World Cup.

[3] On 26 May 1959, Kollmann crashed into two people in Vienna during a drunk driving incident, killing a woman and injuring a student.

In November 1959, he was sentenced to ten months in prison.

This biographical article related to association football in Austria, about a defender, is a stub.