In a prospective material of 1052 patients the precipitating factors, associated symptoms, psychological and neurological deficits have been examined. Mastication and talking are the most frequently occurring precipitating factors, 76% as regards Neuralgia, with typical starting difficulties. As regards Non-neuralgiform Pain 24%, with precipitation late in the masticatory process. There were trigger zones in 50% of the cases of Typical Trigeminal Neuralgia and in 9% of the patients with Non-neuralgiform Pain. In a series of cases the jaw joint is perceived as a trigger zone. Cold precipitates pain in 48%-39%. Other precipitating factors are much more rare--psychological stress in 15% of the patients with Non-neuralgiform Pain, however. "Vegetative" associated symptoms were relatively frequent, lacrimation occurred in 31% of the cases of Typical Trigeminal Neuralgia and in 20% of the cases of Non-neuralgiform Pain. Rhinorrhea and salivation were less frequent. In terms of figures migrainoid associated symptoms had no connection with vegetative associated symptoms or with pain in the eye. In 11% of the patients pain occurred most frequently during the night and in 20% the frequency of pain was the same day and night. About 1/3 of the patients with Neuralgia experienced seasonal variations. Tenderness of foramina is a symptom of no significance. Very few patients had primary sensory loss. No eye or ear symptoms have been found which may be referred to as the patho-anatomical basis of the pain. About 1/3 of the patients with Non-neuralgiform Pain had psychological symptoms whereas hardly any patients with Neuralgia had them. MMPI test performed on a small matched material showed no difference between Neuralgia and Non-neuralgiform Pain. In material B an examination has been made of the jaw joint arthrosis symptoms. A restriction of the diagnosis of arthrosis has had the effect that it must be recognized that patients with facial pain do not have the high frequency of jaw joint diseases previously assumed. As was also the case in a series of normal material previously published, between 1, 5 and 1, 3 of the patients with Neuralgia had jaw joint arthrosis which was due to old age. This study has not revealed any connection between previous diseases, the onset of pain, the character and course of the pain, the character of the attack, the localization of pain, precipitating factors, associated symptoms and symptoms of loss on the one hand and the patho-anatomical substratum on the other.