The Museum of Australian Democracy at Old Parliament House declined protesters' requests to cancel the Australian Family Association event, which featured an address from Dr Quentin Van Meter.

Dr Van Meter is the president of the American College of Pediatricians, which split from the American Academy of Pediatrics over its stance on the rights of gay people to adopt children.

The college has been classified as a hate speech group by the US non-profit Southern Poverty Law Center for its views on LGBTI people.

Dr Van Meter claims transgender people are mentally ill and suffering from a delusional disorder, and argues that allowing children to change their gender is a form of emotional abuse that is not backed up by any scientific evidence.

Canberra man Steve Skitmore, who has several transgender friends, led an unsuccessful last-minute push to have the event shut down on the grounds that it vilified the transgender community.

But while the Museum of Australian Democracy has an internal anti-discrimination policy, it has distanced itself from involvement in allowing Dr Van Meter to speak at Old Parliament House.

"The venue hire spaces are regularly used by external groups who hire space through a separate organisation," the museum said in a statement.

"MoAD does not endorse or review the content of these groups.

"We expect all organisations who use the venue to abide by Australian law."

The organisation that handles venue hire at Old Parliament House, Restaurant Associates, said in a statement that it was "not aware of the topic of the event until discussion appeared on social media the day prior".

Restaurant Associates said it then took precautions to ensure the event was conducted safely.

The company's statement did not address a question asking about the criteria it applied to bookings to make sure they were suitable.

Transgender activist and Australian National University student Florin Giles said forums like the one held on Tuesday night spread dangerous ideas and gave people tools with which to harm transgender people.

"As long as trans people have existed, there's always been people who have not wanted them to exist," he said.

"The right to free speech doesn't negate the right to safe existence."

He said the event being held at a building as symbolic as Old Parliament House was "maybe one of the most offensive things about it".

Initial plans for a protest outside the event were scrapped, but Mr Skitmore and two others decided to buy tickets and attend in support of the transgender community.

Mr Skitmore said they spoke to some of the 70-odd people at the event about why they were opposed to the forum and Dr Van Meter's claims.

"The feedback we got from our transgender friends is that they didn't feel comfortable being there [to voice their concerns] and that it wasn't a safe place for them," Mr Skitmore said.

"... It's these kinds of events that normalise [anti-transgender sentiment] and increase the risk to transgender people.

"There was a whole range of people there that work in community spaces, where they're going to bring these ideas."

Dr Van Meter rejected any suggestion that he peddling hate speech, arguing that his views were backed up by science and that transgender identity was merely a state of mind.

"We're classified as haters, but there is not a shred of hate in anything we do," he said.

"My concepts are based on compassion and science.

"All I'm trying to do is what I believe is my calling, which is to heal patients."

Dr Van Meter said he always invited every member of the audience at his talks to speak to him individually, no matter what their views were or how long he had to stay behind after events.

However, he said people rarely ever approached him with counter-views.

"I will listen to everyone so I can constantly learn," he said.

"We need to have dialogue rather than just shouting across the fence."