The agency will carry out national and trade PR for the 54-mile trek through the Scottish Highlands.
Golley Slater provided advertising and marketing support for the event in 2006, but this year it will also handle the PR, which was previously managed in-house.
The brief covers four key areas, including targeting new media. The agency will encourage participants to blog about their experiences from training walks to fundrasing efforts.
The Caledonian Challenge, which takes place on 16 and 17 June, is one of Scotland's largest fundraising endurance events, challenging teams of of three to six people to walk 54 miles along the West Highland Way. The walk takes more than 24 hours and the aim is to raise money for Scottish grassroots charities and community groups.
The account is lead by Ian Dommet, MD of the Edinburgh office of Golley Slater.