Introduction: In patients with end-stage kidney disease (ESKD), cardiovascular diseases (CVDs) are the most common causes of hospitalization and death. Objective: We aimed to determine the association between dialysis modality and CVDs. Methods: This retrospective observational cohort study compared the emergency hospitalization and mortality of patients with CVDs who underwent peritoneal dialysis (PD) versus hemodialysis (HD). After propensity score matching, the risk factors were evaluated using Cox proportional hazards regression models. Results: A total of 260 patients were matched: 130 of 135 PD (75 men; age, 65.4 years; dialysis vintage, 3.3 years) and 130 of 706 HD (70 men [ p = 0.5]; 66.6 years [ p = 0.4]; dialysis vintage, 3.1 years [ p = 0.5]) patients. Emergency hospitalization rates (hospitalizations/person-years) for overall CVDs (0.138 vs. 0.066, p = 0.002) and pulmonary edema (0.048 vs. 0.019, p = 0.03) were significantly higher in patients who underwent PD than those who underwent HD. The log-rank test revealed that all-cause and CVD mortalities were significantly higher in PD (both p < 0.001). Mortality rates (deaths/person-years) for overall CVDs (0.058 vs. 0.015, p < 0.002), cerebrovascular disease (0.019 vs. 0.004, p = 0.03), and ischemic heart disease (0.010 vs. 0, p = 0.02) were significantly higher in PD. The Cox proportional hazards regression model showed that PD and age were significant predictors of emergency hospitalization (hazard ratio [HR] 2.70; 95% CI 1.53–4.77; p = 0.001) and mortality (HR 4.41; 95% CI 1.66–11.72; p = 0.003) for CVDs. Conclusions: PD is a risk factor for emergency hospitalization and mortality associated with CVDs in dialysis patients with ESKD. Strict control of body fluid balance may prevent cardiovascular events in patients undergoing PD.