The purpose of this study was to examine the relationship between medical services utilization and preventive health behavior and to seek the factors affecting them. Subjects were 568 persons who were from 40 to 59 years old and lived in a community. Preventive health behaviors they actually performed and their interests in health were asked by questionnaire. Preventive health behaviors assessed included smoking behavior, drinking behavior, adequate hours of sleep, physical exercise, regularity of meals, and medical checkups. Medical services utilization, which included the number of visits to medical care providers, was measured by their medical claims during one year. Except for adequate hours of sleep, preventive health behaviors correlated positively with each other. A strong positive correlation was found between medical services utilization and medical checkups. However, correlations between medical services utilization and other preventive health behaviors were not statistically significant. Persons who performed preventive health behaviors and persons who utilized medical services scored higher in interest in health than persons who didn't. These results show that medical services utilization and preventive health behavior are strongly associated with interest in health, but are weakly correlated with each other.