A new report by the United Nations shows the number of deaths caused by Aids-related illnesses has dropped to 1.8 million a year from 2.2 million during the middle of the last decade.
The UNAIDS organisation said the rate of new HIV infections had fallen, as more people than ever before live with the virus.
Along with helping to prolong the lives of those who are HIV positive, scientific studies have shown that antiretroviral drugs also help to drive down the number of onward transmissions.
UNAids estimates 700,000 deaths were averted last year because of better access to treatment.
Globally, the number of people who are HIV positive has reached a record 34 million.
Sub-Saharan Africa has seen the most dramatic improvement, with a 20 per cent rise in people undergoing treatment between 2009 and 2010.
The study, published ahead of World Aids Day on 1st December, celebrates the progress made against the virus.
Executive director of UNAIDS Michel Sidibe, said: “We are on the verge of a significant breakthrough.”
He added: “even in a very difficult financial crisis, countries are delivering results in the Aids response”.
However, the charity Medecins Sans Frontieres, warns of the need to protect global HIV/AIDS funding at a time when many western governments are already cutting spending.
The UNAIDS report also cites the recent calls for home testing kits to be made available in the UK by the Terrence Higgins Trust.
Earlier this year, figures by the UK Health Protection Agency showed that 3,000 gay and bisexual men were diagnosed with HIV last year – the highest number recorded.