The objective of this study was quantitate diastolic dysfunction in the postoperative phase of tetralogy of Fallot (TOF) and to correlate it with the type of surgical procedure and clinical parameters. Fifty consecutive patients (mean age, 5.0 years; mean weight, 13.5 kg), operated for TOF during the period November 2004 to May 2005, were prospectively studied [infundibular resection, 23; infundibular resection and transannular patch (TAP), 19; right ventricle --> pulmonary artery conduit, 8). Detailed echocardiography was done on postoperative days 3 and 9 with a focus on Doppler indices of right ventricular (RV) function, Antegrade late diastolic flow in the right ventricular outflow tract (RVOT) was taken as the marker of restrictive RV physiology. The previous parameters were correlated to the type of surgery and clinical indices of RV dysfunction. There was no mortality. Twenty-four patients showed restrictive RV physiology. This finding correlated with lower values of E/A ratio (0.98 +/- 0.17 vs 1.33 +/- 0.49, p < 0.002), tricuspid valve E-wave deceleration time (86.9 +/- 21.7 vs 151.4 +/- 152 msec, p < 0.05), index of myocardial performance (0.15 +/- 0.06 vs 0.26 +/- 0.09, p < 0.001), isovolumic relaxation time (19.4 +/- 17 vs 39+/-30 msec, p < 0.009), and a higher central venous pressure (15.1 +/- 1.5 vs 12.7 +/- 1.9, p < 0.001). Restrictive RV physiology correlated with prolonged intensive case unit (ICU) stay (5.1 +/- 3.7 vs 2.8 +/- 2 days, p < 0.015), longer duration of inotropic support (108.3 +/- 56.2 vs 55.5 +/- 28.3 hours, p < 0.02), and higher dosage of diuretics. RV diastolic dysfunction is demonstrable by Doppler echocardiography in the first week following surgery for TOF and tends to be worse with TAP. Restrictive physiology demonstrated by RVOT pulse Doppler predicts longer duration of inotropic support, prolonged ICU stay, and higher dosage of diuretics.