St Louis head coach Mike Martz, Green Bay's Mike Sherman, Houston's Dom Capers and New Orleans' Jim Haslett have all been fired by their teams.
Martz watched the Rams struggle in his absence
The Rams had a 6-10 season, and Martz missed the last 11 games with a heart problem. Sherman went after the Packers (4-12) worst campaign in 15 years.
Capers' Texans went 2-14, the NFL's worst mark and poorest in the team's four-season history.
Haslett's homeless and injury-hit Saints were the second worst at 3-13.
The Rams started the season 2-3 before Martz was sidelined with an infection of the heart lining.
Assistant Joe Vitt replaced him for the rest of the season, which ended on Sunday with a 20-10 win over Dallas.
Martz coached the Rams for more than five seasons, leading them to the play-offs four times and to the Super Bowl in 2002, when they lost to New England.
Sherman was 57-39 in six seasons but he was just 2-4 in the play-offs despite winning three consecutive divisional titles.
Sherman's exit could see Packers legend Brett Favre retire
His teams never made it to the NFC Championship game.
Capers, accompanied by owner Bob McNair, told a meeting of Houston's players he had been fired as coach.
McNair said: "We will begin looking for qualified candidates immediately
and get the Texans moving in the right direction in 2006."
In six seasons as Saints coach, Haslett went 45-51. His team struggled in 2004 as well but won their final four games to finish 8-8,
But the 2005 campaign was doomed from the start because of the devastation caused by Hurricane Katrina in late August.
With the Louisiana Superdome out of action, the Saints played their 'home' games in Baton Rouge, San Antonio and New York.
They made a 2-2 start, but went on to lose 11 of their last 12 games.
On Sunday, Minnesota fired coach Mike Tice less than an hour after a win over Chicago, which capped a 9-7 season. Kansas City's Dick Vermeil has retired.