MHP, which is part of the Engine Group, will continue to work with Scottish clients from its London HQ.
Four people worked at the Edinburgh office.
The agency merged its corporate and public affairs functions last year, which were run out of London, Brussels and Edinburgh.
MHP director Ian Kirby told PRWeek: "It became apparent that having a physical office in Scotland was no longer essential to deliver quality service to our clients with interests in the country. We can be more flexible now."
Craig Harrow, managing director of the Edinburgh office, will continue to work with MHP on a freelance basis. The remaining three staff have left the company.
The closure follows the agency's recent announcement that it has formed a partnership with Brussels-based public affairs agency Cabinet DN. MHP’s current Brussels operation will be amalgamated with the Cabinet DN business over the coming months.
Meanwhile, MHP has announced that it has been appointed as the retained financial and corporate PR adviser for TT Electronics, the global electronics firm.