A long-awaited independent report has found sexual harassment and bullying is rife in the NSW parliament, while several people have reported incidents of sexual assault in the workplace.
Mr Perrottet described the report's findings as "sobering, confronting and completely unacceptable".
The investigation, conducted by former sex discrimination commissioner Elizabeth Broderick, found one in five people who work at parliament have experienced sexual harassment in the past five years.
Five people reported an attempted or realised sexual assault, while more than one in four experienced bullying in the past five years, with several unnamed offices identified as "hotspots" for the behaviour.
"Every workplace across our state should be safe from sexual harassment and sexual assault, that is clearly not the case," Mr Perrottet said on Friday.
"Clearly we have a culture in the NSW parliament that over time has become, in many instances, toxic and wrong."
He said the report only marked the beginning of cultural reform at the parliament and pledged to follow through on its recommendations.
They included strengthening internal policies and codes of conduct, reducing alcohol use, boosting support services and monitoring "well-known hotspots" for bullying.
"This must end. It ends today," Mr Perrottet said.
Opposition Leader Chris Minns said no side of politics came to the issue with clean hands.
"It really paints a dark picture of what's been happening," he said.
"We all need to do better, reach across the aisle, and make sure that we're making every possible effort to make the NSW parliament a safe workplace."
Greens MP Jenny Leong said nothing in the report was a surprise and politicians owed it to Macquarie Street workers to end the toxic culture.
"Parliament is a toxic, sexist and at many times unsafe workplace," she said.
Minister for Women Bronnie Taylor said the individuals responsible for the behaviour identified in the report should leave the parliament.
"You know who you are, and my very strong advice to you is that you do not belong in the parliament of NSW," she said.
One in four people working in the building participated in the report, which involved input from MPs as well as political, cleaning, security and catering staff.
Witness statements in the report portray a workplace where people were too afraid or untrusting to speak up against bad behaviour, which was more commonly experienced by young staff.
One person said: "It's very normalised, the MP and chief of staff sleeping with junior staff. The power dynamics were so unbalanced."
"It started as flirting. She can't stop it because it would cost her her job," another said.
Staffers complained parliament was "devastating" on their mental health, and the report said this had caused an exodus of talent.
Long hours, "disgraceful" treatment of staff by MPs, emotionally taxing work and a "real drinking culture" were all cited as part of the toxic culture.
The report notes tenuous work arrangements as an aggravating factor, with one MP describing how they "could walk into my office now and fire all the staff and they have no recourse".
Labor frontbencher Walt Secord apologised on Friday evening for his behaviour in dealing with staff.
"I do acknowledge that I can be too blunt and too direct in a fast-paced workplace – especially in dealing with strict deadlines and highly stressful situations in a time sensitive highly pressurised environment," Mr Secord said in a statement.
"If any parliamentary staff members feel that my conduct in the workplace was unprofessional and caused offence or distress and was unacceptable, I unreservedly apologise."
He vowed to be "part of repairing the culture in state parliament" and to address his "shortcomings".
The independent review was commissioned last year after several complaints were raised about abuse of staff.
Mr Perrottet previously said there was zero tolerance for bullying, days before firing Eleni Petinos as fair trading minister on August 1.
Ms Petinos, who was responsible for keeping the state's workplaces safe, last week rejected accusations of bullying linked to her office.
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