The poor were likely to spend much longer in refugee camps where it is harder to find work or rebuild lives.
Oxfam has called for aid to go to the poorest and most marginalised.
They must not be left out of reconstruction efforts, the charity said.
The tsunami in the Indian Ocean on 26 December killed at least 200,000 people in countries as far apart as Indonesia, Thailand, Sri Lanka and Somalia.
David Loyn, the BBC's developing world correspondent, says it is perhaps not surprising that the poorest suffered the most from the disaster itself.
Living in frail shelter, on marginal land, they were literally swept away by the waves, and the survivors among the poorest communities had less access to medical help than richer people did.
Intolerable gaps
The survey points to the marginalisation of dalits - outcasts in India - and specific problems in Sri Lanka where aid has gone to businesses and landowners rather than the landless.
Six months on, vast swathes of Aceh have not been rebuilt This poverty gap is worst in Aceh, the Indonesian province which was the most badly affected area, already impoverished by conflict before the tsunami hit.
Half a million survivors were homeless.
Yet the wealthier among them have already been able to move out of temporary camps.
Another survey by a group of British academics monitoring the delivery of aid has found that, six months on, there is little evidence of permanent accommodation being built for most people.
It says starkly that these failures would not be tolerated after a disaster in the developed world.
All aid agencies, as well as regional governments must share some blame for this failure, our correspondent adds.
The unprecedented international response to the tragedy means that the immediate humanitarian demands could be fully funded.
Failure to deliver assistance effectively to the poorest, or to plan properly for the future, reveals fundamental weaknesses in the system.
Well, that certainly clears up any questions we had about aid to Africa. DUH!!!
headline leads me to believe Clinton's been skimming; has he ever been around a pile of money that he didn't stick his filthy hands in?
I knew that this would happen. That is the precise reason that I, along with my co-workers did not contribute to any general funds.
We sent our collection of cash to Sri Lanka with a co-worker who was travelling to Sri Lanka to be with his family and organize efforts to rebuild fishing village homes.
We built 30 homes @ $1000.00 each.
Oxfam, stop complaining and call your pal Kofi Annan.
Perhaps all those UN "peacekeepers" could tear themselves away from their heavy schedule of raping and pillaging in Africa long enough to build a few houses in the tsunami area...
Shocked I tell ya.
It's Bush's fault....Bush Sr. of course!
I read somewhere that a lot of those supplies were still on a dock somewhere just going to waste. They can't get it distributed.
OXFAM is a commie organisation. Just putting that out there.
But of course. When has it ever been different?
The USA has thrown away BILLIONS of our dollars in "aid" that today line a bunch of fat cats' pockets.
Anybody surprised?
Anybody that thinks the rich don't get their's even from natural disasters is just plain stupid. I quit giving to any charity because the chances of the money going to somebody who doesn't need it or deserve it IS EXCELLENT. Unfortunately, the greedy on this planet always prosper. Unfortunately, they prosper from the monies given by generous people like AMERICANS who think the money is going to the needy.
NUKE THE UN.
Well DUHHHHHH, this is why I never give the money Uncle Sam doesnt steal from me away.... TO ANYONE!
Didn't Bush give the billion plus to his precious UN to disperse? I guess that means that the billions he gave to the UN for AIDS in Africa didn't get to them either. The UN is a criminal organization and they have no intention of stopping with their criminal activity. Bush needs to take some of the blame for allowing them to continue with their criminal actions by giving them money after they have been caught stealing in the Oil for Food scandal!! His judgment leaves something to be desired.
I tried telling every FReeper not to give a single dime to the Tsunami Shakedown. I hope people listened. I told my fellow workers too and was met with much anger and name-calling. But they have now seen this and are MAD.