Ward 5 at Ninewells Hospital is closed to new admissions due to several cases of vomiting and diarrhoea.
The cause is thought to be norovirus, more commonly known as the winter vomiting bug.
The ward is closed to new patients as a precautionary measure to prevent the spread of the virus.
All appropriate infection prevention and control measures are said to have been put in place.
And NHS Tayside ask that anyone feeling unwell or experiencing vomiting and diarrhoea themselves do not visit friends or family at the hospital.
The health board urge visitors to stay away for at least 48 hours after are they are free of all symptoms.