Ethiopian officials say more than 3300 people were tested for HIV Sunday in the rural region of Gambella.
The massive turnout exceeded expectations among AIDS campaigners, who had hoped to test 2000 people.
Rahel Gettu, an official with the UN Aids agency in Ethiopia, said they believed they broke the world record for the number of HIV tests carried out in one day.
She said their claim was yet to be verified and confirmed by Guinness World Records.
She said 3383 people were tested for HIV within eight hours in a single event ahead of World Aids Day.
Eighty-two of them received positive results.
About 6.5 per cent of Gambella residents have HIV or AIDS, a rate higher than the national average of 1.5 per cent.
Officials hope that voluntary AIDS testing in this region that borders South Sudan can lead to a reduction in the number of new infections.