Background Among the issues caused by the increase of one-person households the health problems and primary medical needs of one-person elderly households among the issues with the increase in one-person households is very important. The purpose of this study was to identified health care needs and problems of one-person elderly households by comparing health behavior, health status, disease prevalence rate, and medical needs to one-person elderly households and multi-person households. Methods Data were obtained from the 2017 Community Health Survey. In this study, 66,211 people who were over 60 years of age without missing variables were included in the final analysis. Results One-person households showed poorer overall health behaviors, such as nutritional behaviors, exercise behaviors, drinking and smoking behaviors, and poorer subjective and objective health status than multi-person households. Furthermore, albeit the high requirement of medical services for mental health outcomes such as suicide attempts, the rate of not receiving services was also high indicating high barriers to receive and access health care. Conclusion Comprehensive and direct comparison of health and medical factors revealed the medical vulnerability and unmet needs in terms of health promotion in the single-person elderly households. These results can be applied as the basic information to understand the needs and medical problems of these risk groups by primary medical doctors who predominantly treat single-person elderly households and can also be used as basic data for policy development in order to solve these unmet medical care needs.