The veteran boss has quit the Barclays Premier League relegation battlers citing his need for double knee replacement surgery in the near future.
His decision on Tuesday came just hours after QPR's failure to land a number of targets on transfer deadline day but Redknapp played down that as a factor and denied a rift with owner Tony Fernandes.
Later in the day Redknapp's first-team coach Glenn Hoddle, the former England manager, also confirmed he had left his position at Loftus Road
Joe Jordan, another member of the backroom staff, is expected to follow while head of football operations Les Ferdinand has taken temporary charge with the support of Chris Ramsey.
Redknapp, who won the FA Cup in charge of Portsmouth and has also managed Bournemouth, West Ham, Southampton and Tottenham, now intends to take time out but is confident he will be back.
The 67-year-old said: "I still don't think I'm finished with football
When I've had the operations, I'll be looking for work again, I know that
I can't imagine my life without it
But right now, I've got to make my health the priority."
Despite Redknapp's reasoning, the timing of his decision will raise questions given his stated desire to bring in players in the winter transfer window.
QPR reportedly failed with attempts to sign several players on Monday, most notably Spurs striker Emmanuel Adebayor and West Ham winger Matt Jarvis.
It then appeared Redknapp and Fernandes might be on collision course as the owner tweeted: "No more cheque book
We have good players
Bought all the players manager asked for in summer
Our players not mercenaries
Good guys."
But Redknapp told the Daily Mail: "I haven't got the hump
We haven't had a row
I knew some while ago that we were not going to be able to get much done in January.
"We had one real target on the last day, Emmanuel Adebayor, because we are short up front
But he was too much money
I accept that.
"There are no hard feelings on my part - I've not had a problem with Tony Fernandes in all my time there."
QPR are 19th in the Premier League with 19 points from 23 games, although they are just a point off 17th.
Redknapp failed to save the club from relegation in 2013 but led them back to the top flight at the first attempt.
They have failed to maintain that momentum this term and Redknapp, due to his condition, feels someone else should now take the reins.
He said: "I'm struggling so badly now
I can't walk, I can barely stand and watch
I'm in pain all the time.
"I've been putting it off and putting it off but it has got to the stage where I cannot do the job.
"It's such an important time
They need someone who can give it everything."
Hoddle, brought in by Redknapp at the start of the season, has spoken of his surprise at developments.
The 57-year-old, in a statement to Zapsportz.com, said: "I am a bit shocked and surprised, to tell you the truth
We all know football is a results-orientated business but I always felt that given a few more games, Harry could have turned it around down there at the bottom.
"It would have only taken a couple of good results to have achieved that as it is very tight down there.
"But that's football for you
I have enjoyed coming back into coaching and I thanked Harry for giving me that opportunity to tip my toe back into the coaching arena."
One of Redknapp's players, midfielder Joey Barton, who looked to be heading out of the club under previous boss Mark Hughes, paid tribute.
Barton tweeted: "Wish Harry well
Enjoyed my time working with him
He was great with me."
Fernandes also said there were no hard feelings.
He said: "We part on good terms and I would personally like to wish him all the best for the future."
Another former Spurs boss, Tim Sherwood, is the early bookmakers' favourite to succeed Redknapp.
Source : PA
Source: PA