Producer Tristram Miall accepted the award, surrounded by many of his collaborators, several of whom had already been up on stage.
They included Elissa Down, who won best director and best original screenplay for the script she co-wrote with Jimmy The Exploder.
One character in the autobiographical family drama has autism and Down actually had two brothers with the condition and thanked her family for letting her 'mine their dirty underwear and make it into cinema'.
Unfinished Sky also won multiple awards. It earned the best adapted screenplay award for director Peter Duncan, several craft awards including best cinematographer for Robert Humphreys, and the two main acting awards for William McInnes and Monic Hendrickx. She was also the lead actress in Dutch film The Polish Bride, upon which Unfinished Sky was based.
In the international acting categories, the late Heath Ledger won for The Dark Knight and Cate Blanchett for Elizabeth: The Golden Age. The International Award for Excellence in Filmmaking went to cinematographer Peter James, who has worked with director Bruce Beresford on many films. Their most recent collaboration is the upcoming Mao's Last Dancer.
Readers of News Limited newspapers, majority owned by Rupert Murdoch along with 20th Century Fox, voted Hugh Jackman their favourite actor while the general public decided that The Castle was Australia's favourite film in a public poll organized to celebrate half a century of AFI Awards.
Television and people who work in television had a big presence at the awards. The stand-outs were the series Underbelly, which is based on true stories from Melbourne's violent gangland killings, relative newcomer Chris Lilley, who created best comedy winner Summer Heights High and won the Byron Kennedy Award, and Dione Gilmour, who won the Raymond Longford Award for her extensive work in natural history documentaries.
The full list of film winners is as follows:
Best Film - The Black Balloon (Tristram Miall)
Best Direction - The Black Balloon (Elissa Down)
Best Original Screenplay - The Black Balloon (Elissa Down, Jimmy The Exploder)
Best Adapted Screenplay - Unfinished Sky (Peter Duncan)
Best Lead Actor - William McInnes (Unfinished Sky)
Best Lead Actress - Monic Hendrickx (Unfinished Sky)International Award for Best Actor - Heath Ledgee (The Dark Knight)
International Award for Best Actress - Cate Blanchett (Elizabeth: The Golden Age)
Young Actor Award - Danielle Catanzariti (Hey Hey It's Esther Blueburger)
Readers' Choice Award -Hugh Jackman
Australia's Favourite Film - The Castle
Best Supporting Actor - Luke Ford (The Black Balloon)
Best Supporting Actress - Toni Collette (The Black Balloon)
Best Documentary - Not Quite Hollywood (Craig Griffin, Michael Lynch)
International Award for Excellence in Filmmaking - Cinematographer Peter James ACS, ASC
AFI Raymond Longford Award - Dione Gilmour
Best Cinematography - Unfinished Sky (Robert Humphreys)
Best Editing - The Black Balloon (Veronika Jenet ASE)
Best Sound - Unfinished Sky (Andrew Plain, Annie Breslin & Will Ward)
Best Original Music Score - Unfinished Sky (Antony Partos)
Best Production Design - Death Defying Acts (Gemma Jackson)
Best Costume Design - The Tender Hook (Cappi Ireland)
Best Short Animation - Dog With Electric Collar (Steve Baker & Damon Escott)
Best Short Fiction Film - Jerrycan (Stuart Parkyn & Julius Avery)
Best Screenplay in a Short Film - The Ground Beneath (Rene Hernandez)
Outstanding Achievement in Short Film Screen Craft (Production Design) - Xanthe Highfield