His head coaching career spanned a total of twenty seasons and also included stints with the Los Angeles Raiders and Washington Redskins.

In 1972, a piercingly hard hit on the practice field ruptured one of his kidneys, which caused his heart to stop for thirty seconds and nearly killed him.

It was his skill as an offensive mind that garnered Shanahan the attention of maverick Oakland Raiders owner Al Davis.

Shanahan (who proved very unpopular with the players) and the micromanaging Davis clashed almost immediately, and this was only exacerbated after the Raiders finished a disappointing 7–9, losing four of their last five games.

Tensions increased towards the end of the season when wide receivers coach and Shanahan loyalist Nick Nicolau got into a heated argument with assistant coach Art Shell (a Davis loyalist) in which Nicolau reportedly accused Shell of having a job only by virtue of his friendship with Davis.

[13] In 1992, Shanahan was hired as offensive coordinator for the San Francisco 49ers under head coach George Seifert, capping his rise with a victory in Super Bowl XXIX after the 1994 season.

[15] Shanahan's success with the 49ers earned him a head coaching spot once more, this time back in Denver with the Broncos beginning in 1995.

He has often found unheralded running backs from later rounds of the annual NFL Draft and then turned them into league-leading rushers behind small-but-powerful offensive lines.

Examples of this phenomenon are Terrell Davis, Mike Anderson, Olandis Gary, Clinton Portis, Reuben Droughns and Tatum Bell, all of whom have had at least one 1,000-yard season in a Denver uniform during Shanahan's tenure.

[17] In 1999, with the assistance of writer Adam Schefter, Shanahan penned Think Like a Champion, a motivational book about leadership; it was published by HarperCollins.

[18] In 2006, he cooperated with Stefan Fatsis's endeavor to spend a year as a Broncos place-kicker, and much of the resulting book A Few Seconds of Panic (2008) covers Shanahan's coaching from the player's point of view.

After Elway's retirement and Davis' career-ending injuries, Shanahan went six years without a playoff win (including three seasons when the Broncos failed to qualify for the postseason),[19] a drought which caused criticism from fans.

[22] In the early part of the 2009 season, it was reported that the Washington Redskins were interested in naming Shanahan their head coach, replacing Jim Zorn.

Although this was reported by several media outlets, the Redskins' vice president of football operations, Vinny Cerrato, stated that a coaching change would not be considered until the end of the season.

The Redskins lost in the Wild Card round of the 2012 NFL Playoffs to the Seattle Seahawks by a score of 24–14, during which his quarterback Robert Griffin III sustained a tear of his LCL and a damaged ACL to his previously injured knee.

[30][31] Griffin underwent reconstructive surgery of his knee on January 9 and returned as the starter for the beginning of the 2013 season, though Shanahan held him out of the preseason to protect him from further injury.

[2][50][51] He and his wife, Peggy, have two children — a son, Kyle, the current San Francisco 49ers' head coach, and a daughter, Krystal.