Jimmy Carter has had 14 stitches after suffering a bad fall while getting ready for church on Sunday.
The Christian and former US president, who celebrated his 95th birthday last week, was left with a black eye after hitting his head in the fall at his home in Plains, Georgia.
Despite the fall, Carter kept a prior engagement appearing at a concert in Tennessee to promote his 36th home construction project for Christian development charity Habitat for Humanity.
An Associated Press video showed him on stage alongside his wife, Rosalynn, 92, with a swollen eye and the stitches visible.
"Well first of all I wanna explain my black eye," he told the audience.
"I got up this morning at my home in Plains (Georgia) getting ready to go to church because right after that we had a family reunion and then we were coming to Nashville and I fell down and hit my forehead on a sharp edge and had to go to the hospital.
"And they put 14 stitches in my forehead and my eye's black as you noticed. But I had a number one priority and that is to come to Nashville to build houses."
Introducing them to the stage was country singer Trisha Yearwood, who called them "the hardest working volunteers you're ever going to meet in your life".
A day later he was out helping to construct the homes in Nashville with Habitat for Humanity.
His wife is volunteering together with him on the building of 21 homes in Nashville this week, with the Carters being assigned work on the porches.
"We'll be doing the best we can," said Carter.