By Chris Hogg
BBC correspondent in Bangkok
Some poor countries do not have the infrastructure to be able to put money donated to fight HIV to good use, experts have said.
Some African countries lack trained health staff
The International Aids Conference in Bangkok heard the health systems in sub-Saharan African and Asia in particular are in a poor state.
Consequently, the World Bank has warned, money is not going where it is needed the most.
The warning has been backed up by the charity Save The Children.
Keith Hanson, from the World Bank's Africa Aids team, said: "We simply don't have enough trained serving physicians and nurses and clinical officers in most developing countries and especially in Africa.
"In some cases we're talking about facilities literally small, simple appropriate clinics in an area where people can get to easily and get what they need."
The Save The Children analysis shows that last year $5bn was raised to fight Aids and HIV - more than ever before.
And in absolute terms the poorest countries do well out of organisations like the Global Fund which provides money for projects to fight Aids, TB and malaria.
They have received two thirds of that organisation's cash to date.
But Douglas Webb from the charity, said when you take into account how many people in these countries are infected, other parts of the world do proportionately a lot better from the Global Fund.
He said: "We're talking about areas like eastern Europe and like Latin America which we found are receiving three times more per infection than regions like sub-Saharan Africa and Asia, which has a much higher disease burden than Europe and Latin America.
"So the countries with smaller epidemics, emerging epidemics are receiving far more money proportionately than the regions which are heavily impacted."
Many at the conference say Aids offers an opportunity for these countries to persuade donors to help them develop decent health care systems for the first time.
What is needed, they say, is a more long term approach by donors - a realisation that investment in basic infrastructure will in time make a real difference in the fight against Aids.