Gavin Orr, from Edinburgh, will take on the Callanish Stones Marathon on the Isle of Lewis on August 2 kitted out in the finest Scottish attire. He is also hoping to raise money for Aberlour Child Care on the way and has already beaten his original £500 target.
Mr Orr, 45, has run 10 marathons since 2008 and even tackled the 53-mile Highland Fling from Milngavie to Tyndrum.
However, he wants to be the fastest man in a kilt and has approached the Guinness World Records to be recognised as the first person to complete a marathon in full Highland dress.
To achieve the world record, he was told to complete the marathon in less than five hours.
He said: "It's a whole lot of cloth - a whole lot of heavy - and if it rains then it'll get a whole lot worse.
"I have done a good few marathons before and I thought fancy dress would be a good way to get a little more money for the charity."