Salicylates lower blood sugar and enhance glucose-stimulated insulin secretion in normal and diabetic man. Although the hypoglycemic effect appears to be mediated by enhanced insulin secretion, extrapancreatic mechanisms cannot be excluded. The mechanism of the enhanced insulin secretion appears to be mediated by prostaglandin synthesis inhibition. The effect of salicylates on insulin secretion mediated by other secretagogues is imprecisely known. In addition to their glucose lowering action, salicylates have been reported to lower free fatty acids, triglycerides, and cholesterol. Salicylates have been imprecisely evaluated as hypoglycemic and hypolipidemic agents. Knowledge of their mechanism of action may provide further insight into the pathogenesis of diabetes mellitus and hyperlipidemic states.