Sarah started her career at the now-defunct Edinburgh Live cable TV station as a runner and production journalist. Within two months of working for the station, she made her first on-screen appearance as a weather presenter.

She joined Grampian Television (now STV North) in August 1998 as a reporter and presenter for North Tonight. Whilst at Grampian, Sarah presented the social affairs series Grampian Midweek, the magazine show Grampian Weekend, and the outdoor pursuits' programme The Great Outdoors. She also presented the travel show Scottish Passport (alongside Bryan Burnett) for Scottish Television

Sarah Mack left Grampian in 2003 to become a full-time mother but then returned to television as a reporter and presenter for BBC Scotland's rural affairs programme Landward, along with fellow presenters Dougie Vipond, Nick Nairn and Euan McIlwraith.