Vaas immediately began his coaching career following his graduation from Holy Cross in 1974. He served as an assistant coach at
Allegheny College in
Meadville, Pennsylvania for five seasons. In 1979, Vaas was hired as the
offensive backfield coach at the
University of New Hampshire in
Durham. He spent four seasons in that capacity before being promoted to the position of
offensive coordinator in 1983. Vaas later went on to serve as the running backs and quarterbacks coach at the University of Notre Dame in 1990 and 1991 respectively. He left Notre Dame to return to his alma mater, Holy Cross, serving as their head football coach in 1992. Following Holy Cross, Vaas went to the Canadian Football League as the offensive coordinator for the Montreal Alouettes. In 1998, Vaas joined NFL Europe as the QB/WR coach with the Barcelona Dragons. Following a World Bowl bid in 1999 with the Dragons, he was named the head coach of the Berlin Thunder. Vaas would lead the Thunder in back-to-back World Bowl Championships in 2001 and 2002. Vaas was named the NFL Europe Coach of the Year in 2002. In 2004, Vaas was named head coach of the new NFL Europe franchise, the Cologne Centurions. Vaas left a successful professional coaching stint to return to Notre Dame in 2005 to serve as QB coach. In 2007, Vaas was named the QB/offensive coordinator at Duke University. Vaas continued his coaching journey at Miami-Ohio serving as the OC in 2009 until he joined the University of South Florida football staff in 2010. Vaas returned to professional coaching in 2020, serving as the offensive coordinator for Team 9 of the XFL. In 2021, he was the head coach of The Spring League Alphas. Presently, Vaas is the assistant supervisor-replay for the Southeastern Conference (SEC). Prior to accepting that role on April 1, 2022, Vaas was an Atlantic Coast Conference (ACC) instant replay official and the supervisor of Colonial, Ivy Patriot League Replay (starting in the 2020 season). In 2022, Vaas served as the instant replay official for the national championship game between The University of Georgia and The University of Alabama. Vaas previously served (2014-2019) as a replay official and communicator for the American Athletic Conference (AAC). Peter Vaas is the owner of Everything Football, LLC.
Allegheny Vaas returned to Allegheny College as the Gators' head coach in 1986, a position he held for four seasons, until 1989. He led the team to back-to-back
North Coast Athletic Conference championships in 1987 and 1988 and earned conference "Coach of the Year" honors both years. His coaching record at the school was 29–11–1. ().
Holy Cross He spent four seasons as the head coach at Holy Cross from 1992 to 1995. His only winning season came in 1992, when he led his squad to a second-place finish in the
Patriot League. ==XFL==