NHS Highland has placed a temporary suspension on visiting at Raigmore Hospital in Inverness to help staff deal with cases of diarrhoea and vomiting.
Ward 2C was closed yesterday after four confirmed cases of norovirus and ward 6C has also been closed due to a number of confirmed cases.
The hospital's infection prevention and control team are monitoring the situation and have placed a temporary suspension on visiting throughout the hospital to prevent the spread of the virus.
Dr Vanda Plecko, NHS Highland's consultant microbiologist, said: "Staff are working very hard to reduce the risk of these infections spreading across the hospital and we continue to appeal for support from the public to help with this.
"We have now put in place a temporary suspension of visiting for all non-essential visitors to help us protect our patients and reduce, as much as possible, the risk of norovirus spreading across the hospital.
"We are grateful for the support staff are receiving from the public and appreciate everyone's understanding and co-operation."
If you feel that visiting is essential, contact the ward first by phone before going to the hospital. NHS Highland insisted no-one should visit a ward unless by prior arrangement with the nurse in charge.
The temporary suspension of visiting will be reviewed at the end of this week.