The purpose of this investigation was to determine the mean salivary flow rate and the prevalence of mouthdryness and its relation to some background variables, such as oral condition, state of health and drug intake, among patients in somatic longterm hospitals. From 154 randomly selected patients salivary samples were taken from both parotid glands with Lashley cannules and 5 min stimulation with citric acid 2%. The sampling was repeated 3 times at a few days interval. The mean parotid flow rate among women was 0.28 ml/min and among men 0.47 ml/min. Forty-three% of the patients had a rate ≤ 0.2 ml/min and 44% of these reported an almost constant sensation of dryness of mouth. Background factors with a significant effect on salivary flow rate could be found only among men taking tricyclic antidepressents especially in combination with diuretics. The flow rates among these institutionalized, old patients as a group were found to be consistently lower than rates found in earlier investigations among healthy old people.