BACKGROUND: Cancer is a leading cause of death worldwide, posing a significant threat to human health and life expectancy. Numerous existing studies explored the correlation between coal-fired power plants and cancer development. Currently, Chungcheongnam-do Province hosts 29 coal-fired power plants, constituting half of the total 58 plants across South Korea. METHODS: This study assessed the cancer incidence by proximity to coal-fired power plants in Chungcheongnam-do Province, Korea. In this study, the exposed group comprised individuals residing within a 2-km radius of the coal-fired power plants, whereas the control group comprised individuals who had no prior residency within the 2-km radius of such plants or elsewhere in the province. Standardized incidence ratios were calculated using the cancer incidence cases retrieved from the National Health Insurance System data from 2007 to 2017. RESULTS: The study found that exposed men had a 1.11 (95% confidence interval [CI], 1.09-1.21) times higher risk of developing all cancer types and a 1.15 (95% CI, 1.09-1.22) times higher risk of developing cancers excluding thyroid cancer compared with control men. Exposed women had a 1.05 (95% CI, 1.00-1.14) times higher risk of developing all cancer types and a 1.06 (95% CI, 0.98-1.13) times higher risk of developing cancers excluding thyroid cancer than did control women. The colorectal, liver, prostate, and bladder cancer incidence rates were significantly higher in exposed men than that in all control groups. The incidence of esophageal, stomach, liver, and lung cancers were significantly higher in exposed women compared with all control groups. CONCLUSION: The residents near coal-fired power plants had a higher risk of developing cancer than did those living in other areas. In the future, long-term follow-up investigations in residents living in the vicinity of power plants are warranted.