He has worked as an assistant coach in the National Football League (NFL) with the Pittsburgh Steelers (1996–1998), Kansas City Chiefs (1999), and New Orleans Saints (2000–2001).
[3] In 2019, he was the special teams coordinator and secondary coach for the Salt Lake Stallions of the Alliance of American Football (AAF).
However, Zook wanted to play Division I football, so he decided to walk on at Miami University in Oxford, Ohio.
He made the team, and by his senior season, Zook was a starting defensive back and a co-captain for the Miami Redskins.
In 1978, Zook began his college football coaching career when he became a graduate assistant at Murray State University.
Beginning in 1991, Zook served as defensive coordinator for three seasons at the University of Florida under head coach Steve Spurrier.
Zook's special teams units performed well enough during the 1994 season that he was offered the defensive coordinator position at Michigan State, prompting Spurrier to give him the title of associate head coach to help keep him at Florida.
However, the NFL's Pittsburgh Steelers offered Zook the job of special teams coordinator just one month later and he accepted, leaving the college game for a time.
In January 2002, Steve Spurrier resigned from Florida to explore head coaching opportunities in the NFL, eventually signing with the Washington Redskins.
Florida athletic director Jeremy Foley sought to replace him with either Denver Broncos coach Mike Shanahan or Oklahoma's Bob Stoops, but each decided to remain with their respective teams.
[11] Given the success of Spurrier's 12-year tenure, expectations at Florida were high, and seemingly settling for Zook was not popular with many students and supporters.
Within a day of Zook's hiring, one fan started a website called FireRonZook.com that gained national media attention.
Many of the losses were fourth quarter comebacks by the opposition, causing many fans to question the prevent defense that was employed.
He did not help his cause by getting into a heated argument with several fraternity members a few weeks earlier after being called in to defuse a dispute between the brothers and his players.
Zook was regarded as a fine recruiter who brought a great deal of talent to Florida during his tenure as head coach.
While the record did not improve, the play on the field did as the Illini nearly upset top ranked Ohio State in Champaign before losing 17–10.
[16][17] More recently, Zook also won over Simeon High School standout Martez Wilson[18][19] along with Florida prospect D'Angelo McCray.
While Zook's team was able to upset Iowa 27–24 a week after their loss to Wisconsin, the Illini finished 2008 with a three-game losing streak at the hands of Western Michigan (23–17), Ohio State (30–20), and Northwestern (27–10).
Zook's team then put together a stunning 38-13 blowout of the Michigan Wolverines in Memorial Stadium, followed up with a 35–32 upset of Minnesota the next week.
However, running back Mikel Leshoure was, and he proved to be an invaluable asset on offense, while Illinois started freshman Nathan Scheelhaase at quarterback.
Illinois then traveled to Penn State to take on a Nittany Lions program that was undefeated at home against the Fighting Illini.
As the 2011 season begun, the Illini were picked by most experts to finish near the bottom of the newly formed Leaders Division.
On the Tuesday before the Wisconsin game, Zook opened his weekly press conference by warning the reporters not to ask questions about his job status.
When reporter Shannon Ryan of the Chicago Tribune asked Zook if he had talked to his players about the rumors pertaining to his future, he walked out of the press conference.
With the loss to the Golden Gophers, Illinois became the first team in NCAA Division I FBS history to start a season 6–0, and end it at 6–6.
[30] On February 28, 2019, Zook joined the Salt Lake Stallions of the Alliance of American Football as special teams coordinator and secondary coach.