Several patients of trigeminal neuralgia were observed pathologically. The results were as follows. 1. Three of five were female and two of five were male. The oldest was 76-year-old man and the youngest 49-year-old woman. The average age was 59.4 years. 2. The main division of involvement was third branch and two cases were combined with infra orbital nerve. 3. There was no constant pathologic changes in nerve tissue, but capillary proliferation were observed in perineural connective tissue in two cases. In one case, there was microneuromatic lesion and mild schwann cell proliferation. But in general, there were nonspecific pathological changes in nerve fiber.