Patients at Southland Hospital in Invercargill are being allowed only one visitor at a time, because of the pressure on hospital staff of increased numbers of patients.
The Southland District Health Board says the limit covers all wards, including the emergency department, until further notice.
Chief operating officer Lexie O'Shea says patient numbers are increasing due to flu viruses and other winter illnesses.
She says cutting visitor numbers will help staff deal with the workload and reduce the number of people moving around the hospital.
Ms O'Shea says it will also help prevent members of the public bringing flu-like illnesses into the hospital.