Three neonatal patients with left-sided congenital diaphragmatic hernia (CDH) were evaluated with echocardiography pre- and postsurgical correction using tissue Doppler imaging (TDI). Tissue Doppler imaging parameters demonstrated improvement after surgery in both left- and right-sided myocardial performance index (MPI); furthermore, both left and right MPI correlated with clinical course in these three patients. These studies suggest that TDI measurements may be prognostic in nature in this patient population, although further studies are needed using this modality in patients with CDH to determine if it may be useful in guiding treatment and to further delineate the reasons why left ventricular function improves.