Parotid and submandibular gland secretions collected from patients with rheumatoid arthritis or systemic sclerosis have been analysed and the results compared with those obtained from a matched group of healthy individuals. Flow rates were measured and the saliva samples assayed for amylase, kallikrein, protein, and salivary IgA concentration. The results showed that only patients with rheumatoid arthritis had a reduced salivary flow, especially parotid flow, with a significantly increased concentration of salivary IgA in both parotid and submandibular saliva. Patients with systemic sclerosis did not show significantly altered salivary flow rates, but there was a marked depletion of salivary IgA content in both parotid and submandibular saliva. Neither disease states appeared to alter the kallikrein or amylase content of saliva. The possible clinical value of these findings is discussed.