Hywel Dda Health Board is restricting visiting to Withybush Hospital, following an outbreak of seasonal flu.
From today (Monday) there is no visiting on Ward 11 other than essential visitors. People wishing to visit should contact the ward for further advice.
From tomorrow (Tuesday) there will be no afternoon visiting, only evening visiting until further notice.
Visiting to all wards at the Haverfordwest hospital is now restricted to two per bed and ward staff have been asked to ensure that this is strictly adhered to.
People suffering from flu or with any symptoms of infection are asked to stay away from the hospital.
Hywel Dda Health Board said the measures were to protect patients and staff and to help reduce the spread of infection.