The main objective of the present study is to find out which factors affect coresidence between older Korean parents and their adult children and to examine the regional patterns of the phenomenon. The 1980, 1995 and 2005 Korea census data are used to investigate the determinants of two types of parent-child coresidence. The two types are coresidence with married adult children and one with unmarried adult children. The study takes advantage of the multilevel mltinomial logit model, allowing the model to capture regional differences. Findings from the study are: (1) Korean parents' coresidence with their married adult children and one with their unmarried adult children are distinctive in their determinants; (2) variables related to wealth or economic status are positively related with possibilities of both types of coresidence; and (3) considerable regional differences in the possibility of coresidence do exist among regions in Korea.