Dietzel's 1958 LSU team concluded an 11–0 season with a win over Clemson in the Sugar Bowl and was a consensus national champion.

Dietzel began his football career in Mansfield, Ohio, where his high school team went undefeated and tied for second in the state.

The 1959 team was ranked first in the country in both wire-service polls until losing to the Tennessee Volunteers, 14–13, in the eighth game of the season.

LSU concluded the season with a 21–0 loss to Ole Miss in the Sugar Bowl, two months after the top-ranked Tigers beat the third-ranked Rebels 7–3 in Tiger Stadium on Billy Cannon's 89-yard punt return, a play that helped win Cannon the Heisman Trophy.

In a 2005 article for the Concordia Sentinel of Ferriday, Louisiana, Dietzel said that leaving LSU was one of the hardest decisions he ever made.

In 1974, amid intense fan pressure, Dietzel announced that he would resign at the end of the season, following an upset loss to Duke as the Gamecocks fell to 0–2.

During the first game of the 1968 season, Dietzel heard the school's band play an arrangement of the Broadway show tune "Step to the Rear" from How Now, Dow Jones.

On the football field, Dietzel ushered his former assistant coach and successor, Charles McClendon, into retirement after 18 seasons at the helm, hiring Bo Rein as McClendon's successor, then turning to former LSU All-American Jerry Stovall when Rein perished in a plane crash on January 10, 1980.

In 2005, Dietzel, along with timber industrialist Roy O. Martin, Jr., the civil rights pioneer Andrew Young, country music artist Kix Brooks, and the LSU woman's basketball coach Sue Gunter were named a "Louisiana Legend" by Louisiana Public Broadcasting.

[7] Dietzel authored a book, Call Me Coach: A Life in College Football, that was published in September 2008 by the Louisiana State University Press.

[8][9] His namesake grandson, Paul Dietzel, II, of Baton Rouge was a Republican candidate for the open seat from Louisiana's 6th congressional district in the nonpartisan blanket primary held on November 4, 2014.