The 42-year-old star is married to wife Deborra-Lee Furness and they have two adopted children - Oscar, 11, and Ava, six.
He spoke to Australia's Herald Sun about the moment they discovered they weren't able to have children naturally.
He said: 'It was painful. It's not easy. You put a lot of time and effort into it, so it's emotional.
'I think any parent can relate - trying to have children is wonderful and when you feel as though that's not going to happen, there's a certain anxiety that goes with it.'
He added: 'We thought we'd have a kid or two biologically and then adopt. But when we decided we'd had enough of IVF, we went ahead with adoption.'
However the couple soon moved on with their plans to become parents.
Jackman said: 'From the moment we started the adoption process, all the anxiety went away. I don't think of them as adopted - they're our children.
'Deb and I are believers in... I suppose you could call it destiny. We feel things happened the way they are meant to. Obviously, biologically wasn't the way we were meant to have children.
'Now, as we go through life together, sure there are challenges, but everyone's in the right place with the right people. It sounds airy-fairy, but it's something we feel very deeply.'