Commons Speaker John Bercow has said several female MPs have told him Prime Minister's Questions is "so bad" they no longer take part.
He said it was worrying that members from both sides of the House "with a lot to contribute" were put off attending the weekly session.
The "histrionics and cacophony of noise are so damaging as to cause them to look elsewhere", he added.
Mr Bercow was speaking exclusively to BBC Radio 4's PM programme.
In the interview, he said: "I'm sorry if some of those people are lost to the chamber because they think, 'I won't take part in that atmosphere.'
"I think it is a big deal. I think it is a real problem. A number of seasoned parliamentarians, who are not shrinking violets, not delicate creatures at all, are saying, 'This is so bad that I am not going to take part, I am not going to come along, I feel embarrassed by it,'" he told us.
In February, Mr Bercow said in the Commons that too many "outstanding" women MPs were standing down from parliament.
In his interview, he expresses concern about disillusionment with politics and urged political leaders to manage expectations better about what they can achieve.
"The statistics don't lie. There is very widespread disengagement with and disapproval of the political process and politicians.
"We certainly do have to dampen down expectations a bit. We can't pretend we are en route to the perfect solution and just give us a bit more time. Let's promise a bit less and deliver a bit better."
Labour MP for Rotherham Sarah Champion told the BBC that the atmosphere at prime minister's questions was "very, very testosterone-fuelled".
"I understand in that sort of environment that people do say and do things that are slightly more extreme than they would do in a normal environment," she said.
"But PMQs is there so that we can have a serious discussion, a serious debate, and ask the right question to our prime minister. The environment we've got at the moment, where it is two teams warring, is just not right."
Ms Champion said sexism was part of the problem.
But she added: "Anything that people can use as a tool to put people off their stride, they will do, whether that's your weight, which team you support, your gender, or your sexuality, you'll hear those comments."
Asked about the implications for Parliament of the row over former Culture Secretary Maria Miller's expenses, Mr Bercow said it had not been well handled by MPs.
He said that when MPs "reach a different view, say from an independent observer or judge, then we have a duty to explain rather better in the media reporting of a row why we've taken a different view. In recent weeks we neglected that duty."
The Parliamentary Commissioner for Standards, who conducted an investigation into the culture secretary's expenses, ruled she should repay £45,000 but the House of Commons Committee on Standards, which has the final say on issues on ethics and disciplinary matters, cut this to £5,800.
The speaker was also quizzed about what changes may be required in Parliament after the trial of his former deputy, Nigel Evans. prompted a debate about working conditions and the culture of behaviour at Westminster.
Mr Evans was accused of one count of rape, five sexual assaults, one attempted sexual assault and two indecent assaults - all of which were dismissed unanimously by a jury.
Mr Bercow said measures should be introduced to offer more support to those working for MPs.
He said: "We're in the process of establishing a confidential helpline that staff can go to and say, 'Look I've got this worry, I'm not being fairly treated, where do I go?' That should be a signposting service that can help them.
"I think each of the political parties, and I've spoken to each of the party whips about this, have got to recognise that it's no good saying that the relationship between the MP and the staffer is sacrosanct.
"The party's reputation and Parliament's reputation suffers if an MP treats a staffer badly and gets way scot-free."