Objectives : There is a paucity of data on the long-term course of obsessive-compulsive disorder (OCD) and chronological relationship between OC symptoms and their related symptoms such as anxiety and depression. The purpose of this study was to investigate the longitudinal course of OC symptoms as well as anxiety and depression which are believed to be associated with OC symptoms. Methods : Data for 155 patients with OCD who completed general evaluation for OCD were used. Forty four were excluded to minimize the effect of the different age of onset on the clinical course. One hundred eleven patients finally participated in the analysis. Cross-sectional correlations between each symptom as well as between such symptoms and the duration of illness were analyzed. Further correlation analysis was done within two groups that were divided by 7 years of the duration of illness. Results : There were significant correlations not only between the severity of OC symptoms and anxiety but also between anxiety and depressive symptom, regardless of the duration of illness. These correlations between such symptoms were also found within patients with the duration of illness below 7 years, whereas these were not within the group with the duration of illness above 8 years. Conclusion : Patients with OCD in this study shows the moderate to severe level of OC symptoms irrespective of the duration of illness. Our finding also suggests that the OC symptoms, especially obsessions are closely related to anxiety and depressive symptoms and these relationships might be pronounced in relatively early phase of the OCD after onset.