End-stage renal disease (ESRD) is a major risk factor for cardiovascular disease and the prognosis after myocardial infarction (MI) is dismal. Although cardiac troponin is a key diagnostic test, troponin levels are often elevated in ESRD patients without evidence of MI. Thus, this study attempted to determine the optimal diagnostic value of high-sensitivity troponin I (hsTnI) by dialysis modality in ESRD patients.Medical records of adult dialysis patients who visited tertiary emergency department (ED) were collected retrospectively. Diagnosis of MI was made according to the fourth universal definition of MI. The cut-off values were calculated using a receiver operating characteristic (ROC) curve.Medical records of 1144 patients were analyzed and MI was diagnosed in 82 patients (75 on hemodialysis and 7 on peritoneal dialysis). The optimal cut-off value of hsTnI in hemodialysis patients was 75 ng/L, with 93.33% sensitivity and 60.76% specificity. Area under the curve (AUC) was .870 (95% confidence interval (CI) .833-.906). The optimal cut-off value of hsTnI in peritoneal dialysis patients was 144 ng/L, with 100.00% sensitivity and 83.10% specificity. AUC was .943 (95% CI .893-.992).The dialysis modality should also be considered when diagnosing MI using hsTnI in ESRD patients.