The object was to determine the relative importance of the sympathetic and parasympathetic innervation of the rat parotid gland in (a) the secretion of amylase during natural feeding (b) the synthesis of amylase during fasting and (c) the production of saliva. Under Avertin anaesthesia, the preganglionic cervical sympathetic or auriculo-temporal nerve was sectioned on the right. Glands on the left acted as controls. Amylase was determined in gland homogenates prepared in aqueous Triton X-100. Sympathectomy markedly prevented the amylase depletion seen in control glands after 1–1 1 2 hr feeding in previously fasted animals, but did not impair resynthesis during fasting. Parasympathectomy also restricted amylase release during feeding, but to a smaller extent. This finding was attributed to the large reduction in salivary secretion rate. Sympathectomy did not reduce flow-rates in response to gustatory stimulation in conscious rats. A technique was developed which allowed saliva to be collected during feeding. Although Sympathectomy reduced the amylase concentration in saliva, the secretion of amylase under these conditions seemed less dependent upon an intact sympathetic innervation than in the gland analyses. The most probable explanation for this is that in rats with cannulated ducts the pattern of eating might be different from normal because of a drying of the mouth and discomfort when chewing and also that the duration of feeding was short.