Introduction: Being infected with COVID-19 is associated with direct and indirect effects on the cardiopulmonary system and electrocardiography can aid in management of patients through rapid and early identification of these adversities. Objective: The present study was designed aiming to evaluate electrocardiographic changes and their correlation with the outcome of COVID-19 patients. Methods: This Prospective cohort study was carried out on COVID-19 cases admitted to the emergency department of an educational hospital, during late February and March 2020. Electrocardiographic characteristics of patients and their association with in-hospital mortality were investigated. Results: One hundred and nineteen cases with the mean age of 60.52±13.45 (range: 29-89) years were studied (65.5% male). Dysrhythmia was detected in 22 (18.4%) cases. T-wave inversion (28.6%), pulmonale P-wave (19.3%), left axis deviation (19.3%), and ST-segment depression (16.8%) were among the most frequently detected electrocardiographic abnormalities, respectively. Twelve (10.1%) cases died. There was a significant correlation between in-hospital mortality and history of diabetes mellitus (p=0.007), quick SOFA score > 2 (p<0.0001), premature ventricular contraction (PVC) (p=0.003), left axis deviation (LAD) (p=0.039), pulmonale P-wave (p<0.001), biphasic P-wave (p<0.001), inverted T-wave (p=0.002), ST-depression (p=0.027), and atrioventricular (AV) node block (p=0.002). Multivariate cox regression showed that history of diabetes mellitus, and presence of PVC and pulmonale P-wave were independent prognostic factors of mortality. Conclusions: Based on the findings of the present study, 18.4% of COVID-19 patients had presented with some kind of dysrhythmia and in addition to history of diabetes, presence of PVC and pulmonale P-wave were among the independent prognostic factors of mortality in COVID-19 patients