A homegrown documentary about former Prime Minister Helen Clark's campaign for the top job at the United Nations will have its New Zealand premiere today.

But the star herself won't be there to see the lights dim at The Civic for the screening of My Year with Helen as part of the New Zealand International Film Festival (NZIFF) this afternoon.

Travel commitments mean Clark - who led the Government for nine years and was our first elected female PM - won't be in attendance; with the former PM travels in the past week taking her to Siberia, Mongolia and Russia.

After resigning from the Labour Party in 2008, Clark served as administrator of the UN's Development Programme for eight years until April 2017.

She ran for the position of Secretary General after Ban Ki-moon announced his retirement in 2016 but lost to former Portugal Prime Minister Antonio Guterres.

My Year with Helen, directed by New Zealander Gaylene Preston, chronicles Clark's campaign for the leadership of the UN.

"This is a film about a woman who has led New Zealand, who has before she left New Zealand been in the top 25 of the Forbes' most influential women in the world list for many, many years and remains so," Preston told the Herald on Sunday.

"I think the film just illuminates the work she's done. It takes you right to the door of the old boys' club and leaves you there."

It received a standing ovation at its first screening Sydney Film Festival recently, but Loader said showing it here would be different.

"Helen is us. Although the film doesn't have anything to do with local politics, nevertheless she's ours so it's like a home crowd is always going to be different."

Clark has long been admired for breaking through the gender glass ceiling.

"That can't be underestimated because I think that we have got a less gender bound society in terms of a lot of things when we compare with other places," Preston said.

"We have a certain 'roll your sleeves up, get your gum boots on and get on with it' kind of culture at our heart.

"Helen is very much a leader like that and she has a very practical approach to things. I think that practical approach means she has a very clear mission when she's deciding to do something and she divides it up into steps and she just does it."

After the screening Preston will host a Q&A with audience members

"Once I've made a film it's up to the audience to decide what they think," she said.

"My Year with Helen is a living document. It captures a time and a place with a very particular world leader striding through it. We are looking at global politics and how it sits for women in a greater since.

"In a way although it's about Helen, it's actually about a much bigger thing which is female leadership and female empowerment."

Whether people loved or hated Clark, they had to admire her," Preston said.

"She's taking care of business and the business she's taking care of is trying to leave the world a better place than how she found it."