Visitors to the Edinburgh International Conference Centre (EICC) injected a record £50.4 million into the city last year after an extension doubled capacity at the venue.
The new £30m Lennox Suite means the council-owned facility can cater for 3,000 delegates.
Its opening meant that longer duration international events with greater delegate numbers pushed the economic impact measure past the previous high of £35.6m in 2012.
The assessment of its economic impact is derived from the spending power of international business tourists attending major conferences. Councillor Gordon Munro, EICC chair, said: “It is encouraging to see such an early payback to the city from this investment.”
The expanded centre has recently hosted, among others: 2,150 delegates attending and international investigative dermatology conference over seven days; the European Space Agency’s living planet symposium, which involved 1,800 delegates over eight days; and the Linux Foundation’s week-long automotive summit for 850 delegates.