This study attempts to estimate the levels and trends of fertility for small geographical areas during the period 1961-1980 in the Republic of Korea, based primarily on the sample enumeration data of the 1970, 1975 and 1980 censuses. The own-children method was employed, after adjusting the data for the underenumeration of children and women, and mortality conditions experienced by them. In general, current estimates for the whole country are in close agreement with various estimates done by others based on different methods and data, and reveal various consistent patterns and trends of fertility.