Objectives : The aim of this study is to investigate the relevant factors which determine the use of oriental healthcare services among subjects with chronic illnesses. Method : This study utilized the data from the Korean National Health and Nutrition Examination Survey in 2005. Out of all the participants of the survey, 11,665 individuals who are older than 19 years old and have one or more chronic diseases were included in this study. Results : The factors that affect utilization of oriental healthcare services were significantly associated with gender, educational level, job, personal income, the number of chronic illnesses, experiences of nontreatment or delayed treatment and admission experiences for the last one year(p<.001). Although some of these factors need further studies, the determining factors for the use of oriental healthcare services are the presence of chronic illness and the number of chronic disease. That is, the chronically ill are more likely to seek oriental healthcare services. And the more chronic diseases the clients have the higher probability of seeking oriental healthcare services was found. Conclusions : The results suggest that the national integrated care services should be established for diverse development of policy regarding the quality of care of chronic illness and cost-effectiveness.