Characteristcs of environmental health conditions in Manabe island were surveyed from the standpoint of public health. The results obtained were as follows: 1. Those employed in primary industries (fishing and farming) are greater in proportion in Manabe Island while those employed in secondary industries are higher in number in Kasaoka City excluding Manabe Island. 2. The population of aged people and the dependence population index in Manabe Island were higher than those in Kasaoka City, a trend thought to be characteristic of isolated islands in the Inland Sea. 3. The ratio of aged people and proportional mortality indicator (PMI) were higher in Manabe Island than that in Kasaoka City. 4. Heart disease, injury of extremities, liver disease, and parasytosis showed a higher incidence in people who belonged to national health insurance in Manabe Island than those of Kasaoka City excluding Manabe Island.