BACKGROUND: The growing demand for quick and convenient meals has altered eating behaviors and contributed to the rise in convenience stores in South Korea. Convenience stores often provide energy-dense, nutrient-poor foods, which may contribute to unhealthy eating behaviors and increase chronic disease risk. This study aims to examine the association of convenience store density with the prevalence of chronic diseases across 250 districts in South Korea. METHODS: District-level data on the prevalence of obesity and hypertension, as well as covariates, were obtained from the 2022 Korea Community Health Survey. Data on convenience stores were sourced from the 2022 Census on Establishments. Moran's I and LISA analyses were conducted to assess and identify spatial autocorrelation and clustering patterns in obesity and hypertension prevalence across South Korea. Additionally, ordinary least squares (OLS) regression and spatial error model (SEM) were employed to examine the association between convenience store density and disease prevalence. RESULTS: The results of the OLS model indicated that convenience store density was associated with both obesity and hypertension in South Korea; however, only its association with hypertension was found to be significant, after adjusting for spatial autocorrelation using the SEM. The prevalence of hypertension increased by 0.968% for each additional convenience store per 1,000 people. CONCLUSION: Convenience store density was significantly associated with hypertension, even after accounting for spatial autocorrelation. These findings highlight the need for further research and policy interventions to mitigate the health risks associated with convenience store density in influencing hypertension and obesity.