BACKGROUND: The functional dyspepsia gives rise to such a symptom similar to peptic ulcer without showing a noticeable lesion(e.g, gastric or duodenal ulcer) by endoscopy or upper GI serises, and it has been known that this is about twice as many as the peptic ulcer. However, there is no exact theory about its pathophysiology and it is suggested that multiple factors including genetic, physiologic, psychologic, environmental factors are engaged. Especially, in respect to the occurrence of functional dyspepsia and psychological factors, there have been many clinical studies over the world. But, we still need more studies in this country, therefore, this study has been initiated to give help patients of functional dyspepsia, invest.igating their characteristic traits through MMPI. METHODS: From March to September in 1996, the patients who visited the family medicine out-patients department of St. Marys hospital of Catholic Medical College were sampled in this study. There were 46 patients having a similar symptoms to peptic ulcer without showing pathologic lesions by endoscopy. Through an interview and some basic tests, the 41 controls who had no dyspeptic symptoms and were not affected to a noticeable physical or physiological disorders were selected for the normal reference group. The standardized MMPI of our country was applied to the whole object groups to get a result. Then each average value of the measure(mean T-score) was calculated, and the differences of the average value were analyzed by the t-test and chi-square test. And the psychological pattern analysis was done. RESULTS: In demographic aspects, there were no significant differences between the two groups. The mean T score for each measure of the two groups falls within the normal ranges with their values being of between 30 to 70. And the average of L, F, and K measure, known as the validity measure, did not give a significant differences between the two groups. The measure of Hs, D, and Hy have appeared significantly high in the patients group(p<0.01) and the Pd measure, too(p<0.05). While Mf, Pa, and Ma measure have not shown a significant differences, Pt, Sc, and Si measure have very significant differences(p<0.01). CONCLUSIONS: In the patient group with the functional dyspepsia, the measures of Hs, D, and Hy where they indicate a neurotic pattern have shown a very significantly high point as well as those of Pd, Pt, Sc, and Si where they indicate a psychotic pattern. This reveals that in the group of the functional dyspepsia neurotic or psychotic trends to attribute. However, it is very hard to define the characteristics of a group with just one test, so further study with more variable test will be necessary.