A Georgian waitress who offered one of her own kidneys to a complete stranger last year has marked their enduring relationship almost a year on.

Hooters waitress Mariana Villarreal was serving a customer – Don Thomas – in May, 2016 when she learned the man had lost both kidneys.

"I said, 'Well I have two kidneys, do you want one of mine?'" Ms Villarreal told local broadcaster WXIA .

While surprised at this spontaneous offer, Mr Thomas ultimately accepted.

Ms Villarreal said her decision was inspired by the fact she was unable to save her own grandmother from kidney failure.

"I wasn't able to do anything for my grandma," she said.

"If (Don) can live two more years, happy as he's ever been, that's fine with me.”

The resulting surgery proved a success, with the experience leaving Ms Villarreal and Mr Thomas fast friends.

In a post to Instagram last week, Ms Villarreal said the pair see each other at least two to three times a month.

“He's doing amazing! No kidney problems at all! #friendsforlife,” she wrote.

The post has received hundreds of likes.

To find out how you can donate your organs to help others in need, visit the DonateLife website .