Both animal and human data suggest that polyunsaturated fatty acids of n-6 and n-3 series may play a role in blood pressure regulation. The majority of dietary intervention studies have shown that changing from a high fat, low linoleic acid diet to a low fat, high linoleic acid diet lowers blood pressure. However, controlled, double-bind studies do not support the independent effect of linoleic acid. Polyunsaturated n-3 fish fatty acids lower blood pressure but only in pharmacological doses that cannot generally be recommended. The mechanisms of blood pressure regulation by n-6 and n-3 fatty acids seem to be related to prostaglandin metabolism.