Muslim leaders from around the country who were in Houston for the volunteer effort said the anniversary was coincidental.
But they welcomed the opportunity to highlight their faith's true meaning.
"We're not trying to prove anything, other than what our faith requires us to do," said Mahdi Bray, executive director of the Washington, DC-based Muslim American Society.
"What goes with our faith is to help others, to respond and show compassion when people need it, and I'm glad we can do it."
Parvez Ahmed, chairman of the board of the non-profit Council on American-Islamic Relations (CAIR), said Muslim leaders viewed Sunday's volunteer opportunity as another chance to show that the 11 September attacks were carried out by Islamic extremists who do not represent the true meaning of their faith.
Religious and community groups who volunteered to help at shelters picked through a random drawing what day they would work. Houston's Muslim community got Sunday.
"If today not only happens to be a day where we are feeding people and helping people and doing our Islamic duties ... but at the same time it also presents an opportunity to dispel myths about Islam and terrorism, then so be it," Ahmed said.
"You find people of different faiths coming together, working together, feeding the poor. It's amazing. It's a wonderful feeling"
Dallas computer consultant
CAIR, along with other Muslim groups such as Islamic Relief and the Muslim American Society, are part of the Muslim Hurricane Relief Task Force, which is raising $10 million for victims of Katrina.
Ahmed said the groups have raised between $3 million and $4 million.
Anwar Ali, a computer consultant from Dallas, began his volunteer shift at 4am (0900 GMT) on Sunday and was still working by mid-afternoon.
He had brought carts filled with food to the cafeteria area and helped elderly people walk from one part of the convention centre to another.
"You find people of different faiths coming together, working together, feeding the poor. It's amazing. It's a wonderful feeling," said Ali, 38, who was scheduled to be in Houston this week on a work-related project but came to town late on Saturday so he could volunteer.