BACKGROUND: Shigellosis is one of the most important contagious diseases in Korea. Especially, Jeju island has been known as the main and large outbreak area in Korea. The purpose of this study was to investigate the epidemiologic characteristics of shigellosis in Jeju island, 2003. METHODS: Patients with shigellosis, confirmed by culture in Jeju island in 2003, were included in this study. We retrospectively reviewed epidemiologic questionnaires, medical records, and official documents. We also collected data from direct interview with the patients with shigellosis. Epidemiological analysis was performed by 3 categorized events and ages. RESULTS: Ninety-nine patients were included in this study. S. sonnei was identified in all of the patients. Shigellosis mainly occurred in preschool-aged children. However, there was no statistical difference according to sex. Although there were asymptomatic cases (15.15%), the chief complaints were loose stool (69.7%) and abdominal pain (12.12%). Initial symptoms in symptomatic patients were abdominal pain (43.43%) and fever (31.31%). The median duration of isolation in the hospital was 7 days. CONCLUSION: Large and chronic epidemic outbreaks of shigellosis have occurred in Jeju island. Throughout this survey, we could show the epidemiological characteristics and the nature of shigellosis in Jeju island.