HomeGround Services, which helps find crisis accommodation for homeless people in Melbourne, said 14 delegates from African nations including Uganda and Tanzania had sought their help.
"We've had 14 people so far come in," spokeswoman Cathy Beadnell told AFP.
"Obviously they have nowhere to live at the moment. They are all moving towards making asylum claims."
The Asylum Seeker Resource Centre, also in Melbourne, said they believed up to 25 people had sought advice on how to remain in Australia once their visas had expired.
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It heard that such laws targeted minorities who bore a disproportionate share of the global pandemic, and created conditions under which HIV can spread.
"Clearly they are delegates that come from countries where to work in the AIDS field is a life-threatening proposition," the centre's Pamela Curr told the Australian Broadcasting Corporation."It seems that some of them have been considering whether they think they can survive in their countries of origin, or whether they should try to survive by getting refugee protection in Australia."
"All claims for protection are considered on their individual merits and according to law," the spokeswoman said.
The 20th International AIDS conference, which was addressed by former United States president Bill Clinton and rocker Bob Geldof, was attended by about 13,600 people from more than 200 nations.
It is not the first time visitors have sought asylum in Australia after attending a high-profile event, with 15 players in the 2008 Homeless World Cup football tournament staying on.
Australia denies asylum-seekers who come by boat resettlement, sending them to Papua New Guinea and Nauru, but those who come by plane are not subject to the same conditions.