A pets as therapy (PAT) programme was initiated in a closed ward of a major psychiatric hospital. The effect of regular contact with a dog on a selected group of chronic ward-bound patients suffering from dementia was assessed over a 12 week period using a number of measures. These included global measures of daily functioning, physiological measures (blood pressure and heart rate) and a measure of general ward noise levels. A matched group from a similar closed ward was used as a control. Results indicated significant experimental group changes in heart rate and a substantial drop in noise levels in the experimental ward during the presence of the dog.