In the three months to 25 January the producer AG Barr said trading performance is expected to have been well ahead of total soft drinks market.
Full year revenue is expected to be around £259m, a year-on-year growth of close to two per cent.
Chief executive Roger White said sales were boosted in the final days of the year when it emerged Scottish nurse Pauline Cafferkey who survived Ebola praised Irn-Bru as a key part of her recovery from the virus.
The media coverage added to the publicity for the brand, which also had a sponsorship deal with the Glasgow Commonwealth Games.
AG Barr said it remained on course to profit expectations.
The company had a merger proposal rejected from larger British rival Britvic in July 2013.