First-time entrant Allie Campbell has won the $7,500 prize for her paintings of Prime Minister Julia Gillard and Opposition Leader Tony Abbott.
The portraits are framed by bedpans, giving the impression that the pair are in a toilet.
Ms Campbell, a former aged-care worker, says she managed to acquire the bedpans during a visit to a hospital.
"I actually went to a hospital to ask for them and ... when they found out what I wanted them for they gave them to me for free," she told AAP.
Now in its 18th year, the Bald Archy prize was contested by 42 finalists who entered caricatures of Australian celebrities and politicians.
Media doyenne Ita Buttrose, federal MP Bob Katter and cricket legend Shane Warne are among those portrayed in the competition.
The competition parodies the NSW Art Gallery's Archibald Prize for portraiture.
