Postoperative coarctation (CoA) patients are often found to have signs of persistent myocardial dysfunction. M-mode echocardiography was performed to study left ventricular (LV) size, mass, and systolic function and Doppler ultrasonography to study LV filling and flow velocity in the LV outflow tract and aorta in 28 ``healthy'' postoperative CoA patients (5–21 years) and 28 age- and sex-matched controls. The early (E) and late (A) diastolic transmitral velocities were significantly higher in the patient group than in the controls (p < 0.05). Other diastolic parameters (isovolumic relaxation time, E/A ratio, and deceleration time of the early diastolic velocity) were similar in the two groups (p= NS). The left atrial diameter, LV wall average, end-diastolic diameter of the LV and LV mass were higher in the patients than controls (p < 0.05). The patients also had a higher stroke volume, cardiac output, and cardiac index than the controls (p < 0.01). The fractional shortening was similar in the two groups (p= NS). Blood flow velocities in both the LV outflow tract and aorta were higher in the patients than the controls (p < 0.0002). We found LV hypertrophy with signs of a hyperdynamic circulation (increased cardiac index and stroke volume) in our patients. An increase in A is associated with LV hypertrophy and seems to be a sensitive marker of diastolic abnormality. The rise in E is paradoxical but has been seen in other studies. The increased blood flow velocity in the LV outflow tract suggests obstruction to LV outflow and increased flow in the descending aorta is due to residual coarctation.