This study was conducted to investigate the prevalence of unmet need based on both subjective assessment and adjustments for need-predicted utilization and to examine factors associated with them. Data from the Fourth Korea National Health and Nutrition Examination Survey, a population-based, cross-sectional study, were used in this study. Participants included 11 620 Koreans (4959 males and 6661 females) aged 19 and older. The results for subjective unmet need suggested that female or younger individuals were more likely to experience unmet need, compared to male or older individuals. Those residing outside the capital had a higher likelihood of experiencing unmet need. Lower levels of education showed an association with higher odds of having unmet need. This study found similar results for the adjusted unmet need. The findings of this study suggest that location and education are more important factors associated with unmet need than income levels.