The mechanism of myocardial damage in dengue could be the release of inflammatory mediators or the direct action of the dengue virus on myocytes leading to myocarditis. The release of inflammatory mediators is more in a severe form of the disease that correlates to the higher incidence of cardiac manifestations in patients with severe dengue. To determine the electrocardiographic and two-dimensional (2D)-echocardiographic findings in children with dengue infection and to find a correlation with disease severity. A total of 150 children between 1 month and 12 years of age seropositive for dengue Non-specific antigen 1 (NS1) Enzyme linked immunosorbent assay (ELISA) or dengue Immunoglobulin M (IgM) ELISA were studied in the Department of Pediatric Medicine of a tertiary care government hospital. The patients were undertaken for 12 lead electrocardiograms (ECGs) and echocardiograms. Out of the 150 dengue seropositive cases, 61 cases were of mild dengue, 67 cases were of dengue with warning signs (DWSS), and 22 cases were severe dengue cases. Abnormal ECG was found in 78 cases (52%) in a total of 150 cases in terms of rate, prolonged PR interval (interval between atrial depolarization and ventricular activation), ST (ventricular repolarisation)-segment depression, and low-voltage complexes. Abnormal 2D- echocardiography (ECHO) was found in 70 (46.6%) out of 150 in terms of the ejection fraction (EF) <55%, Early diastole/atrial contraction (E/A) ratio <1, and the presence of pericardial effusion. Nearly 50% of the patients have abnormal ECG and ECHO findings, more so in the severe dengue group. There is a statistically significant association of the EF between mild dengue, DWWS with severe dengue (P =0.001).