The agency said the severity of the quake had made work very difficult and urged the international community to get as much aid to Haiti as possible in the coming days.
Jean-Claude Fignole, ActionAid's Haiti country director, said: "Haiti needs a massive clean-up operation. There are bodies everywhere, and hundreds of thousands of survivors are living in very close proximity to the dead. The potential for sickness and disease is staggering. We need to see a massive international aid effort arriving as soon as possible.
"I am standing just across the road from a children's school which collapsed with hundreds of children inside, but there is no clean-up happening.
"Hundreds of thousands of people are sleeping in tents, or filling public squares waiting for some kind of help. There is no water, food or sanitation. Many of the survivors have broken arms and legs."
ActionAid said its emergency response was in its initial phase but conditions were very difficult given there were no working phones, its office was unsafe and many staff members were themselves affected by the earthquake.
"Communication is next to impossible as the phones are down. We are working from a temporary office and trying to get our programmes started. Many other aid agencies and the UN have been badly affected. But we will be able to start giving out aid soon," said Fignole.
ActionAid has a long-established programme in Haiti. Our staff is already there working with communities and helping the poorest and most vulnerable people.
ActionAid is initially planning to distribute food, shelter and essential goods like soap and blankets to around 20,000 people. In the longer term ActionAid will work in partnership with Haitian organizations to rebuild the houses of poor men and women and their livelihoods.
We urgently need =A3800,000 for immediate relief. This could provide water, food and shelter for around 20,000 people. We will also continue our work with communities as they rebuild their lives by restoring livelihoods and helping people recover from the trauma of the earthquake.
=A310 could help provide water to 25 families for a day
=A336 could help supply a kit of vital supplies to a family who have lost everything
=A350 could help provide temporary shelter for a whole family