Objective: This study aimed to examine the associations between regional care system factors and dementia care center registration rates across 17 provinces in South Korea. Methods: A secondary data analysis was conducted using publicly available statistical data from 2023. The dependent variable was the registration rate of Dementia Care Centers. Independent variables included the proportion of older adults, the long-term care certification rate, the cognitive screening rate, and the rate of suspected cognitive impairment. Descriptive statistics and Pearson correlation analyses were performed, followed by hierarchical regression analysis to examine the incremental explanatory power of structural and access-related factors. Results: Substantial regional variation was observed in dementia care center registration rates. Hierarchical regression analysis revealed that the long-term care certification rate was the strongest positive predictor of registration rates, and the proportion of older adults was also significantly associated. In contrast, the cognitive screening rate showed a significant negative association in the final model. Conclusion: The findings suggest that dementia care center registration rates are more closely associated with the operational maturity of regional long-term care systems than with the mere expansion of screening access. These results highlight the importance of integrating screening, registration, and long-term care services within community-based care systems.