Children with ventricular septal defects (VSDs) are subjected to hemodynamic overload which causes myocardial injury and subsequent heart failure. Early stages of myocardial damage cannot be detected by conventional echocardiography. Two-dimensional speckle tracking echocardiography (2D-STE) and cardiac troponin I (cTnI) have been recently introduced as more accurate tools for early assessment of cardiovascular diseases. The purpose of this study is to evaluate the role of cardiac troponin I (cTnI) and 2D-STE in the early detection of VSD-induced myocardial injury. Thirty children with VSD (symptomatic and asymptomatic) and 30 controls were assessed serologically by measuring serum cTnI and by conventional echocardiography. STE was performed to measure the averaged global peak longitudinal systolic stain [G peak SL(AVG)]. Serum cTnI levels were significantly higher in patients when compared to controls (P < 0.05) and in the symptomatic group when compared to the asymptomatic group (P < 0.05). Serum cTn I level correlated positively with the left atrial (r = 0.37, P = 0.045) and left ventricular dimensions (r = 0.46, P = 0.01) and negatively with the G peak SL(AVG) (r = −0.39, P = 0.03). There were no statistically significant differences between patients and controls or between symptomatic and asymptomatic groups with regard to the G peak SL(AVG). The peak longitudinal systolic strain (measured by 2D-STE) is not affected despite the elevation of serum cTnI. Serum cTnI is a sensitive marker for early detection of myocardial injury in VSD patients even before the development of ventricular dilatation or dysfunction.