The five year contract is expected to represent a total value of at least £30m.
The contract was awarded under the Government Procurement Service FM framework agreement.
The contract starts on 1 October 2012 and covers more than 80 buildings across Scotland. It includes specialist scientific facilities in Edinburgh, Aberdeen and Perthshire as well as bodies such as the Student Awards Agency for Scotland, Science & Advice for Scottish Agriculture, Accountant in Bankruptcy and the Scottish Fire Services College.
Mitie said that it would deliver more than 95% of the services itself. These include M&E maintenance, project delivery, energy management, cleaning and a range of soft services.
Mitie has already been working for the Scottish government for seven years and the increased scope of this new contract is expected to offer economies of scale.