Dopamine is known as an inhibitor of Prolactin (PRL) secretion; Prostaglandin F 2a is known as a stimulatorof its production. These effects probably occur at the hypophisis. Prostaglandins are thought to be involved inthe mechanism of migraine attacks. Prolactin response (as plasma levels) to L-dope inhibitory test wasmeasured in migrainous patients. Two different Prolactin curves were obtained during the migrainous attacks,according to the type of the migraine, common and complicated.It was found that during an attack of a common migraine, Prolactin plasma levels were reduced in responseto L-dope loading test, while during an attack of complicated migraine a hyperprolactinemic curve wasobtained.The significant difference elaborated statistically, can not be explained by one single factor, like serotonin,which is supposed to be involved in the mechanism of both types of migraine; therefore we have to assumethat another factor associated with Prolactin secretion is specifically connected to complicated type ofmigraine. It is suggested that the hyperprolactinemic responses may indicate an interaction between L-dopaand Prostaglandin F 2a , and should be considered as an indirect evidence that Prostaglandin F 2a is involved inthe mechanism of the complicated migraine attacks, but not in common migraine.