A stomach bug has forced the Duchess of Cornwall to cancel her first royal engagement of the year.
Camilla will visit the United States later this month with Prince Charles
She had been scheduled to open the Health Sciences building and receive a tour of the University of Aberdeen's medical school.
But a royal spokeswoman said Camilla was too ill to visit the new £5.7m facility.
Last month a bout of gastro-enteritis forced her to abandon a tour of a Christmas pudding factory.
Her spokeswoman said: "The duchess has caught a gastric bug and does hope to reschedule the visit."
The schedule for Camilla would have included a tour of the building, one of Europe's major centres for researching improved treatments for major diseases.
Camilla, who is president of the National Osteoporosis Society, was due to have been shown a new £90,000 bone scanner by Professor David Reid, an expert in the field.
She was also due to meet scientists studying Alzheimer's and dementia, and others trying to prevent childhood deaths in the developing world.
On 8 December, a similar illness forced her to cancel an engagement at the Matthew Walker Christmas pudding factory in Heanor, Derbyshire.
A University of Aberdeen spokeswoman said staff at the Foresterhill campus were disappointed Camilla had been unable to attend.
She added: "All of us at the university wish the duchess a speedy recovery, and we would hope to welcome her again."
Earlier this week it was announced she would visit the United States later this month with her husband, Prince Charles.
The royal couple will be in Philadelphia and New York on 27 and 28 January.