With the recent advances in pediatric cardiology and cardiovascular surgery, assessment of ventricular function in single ventricle complexes is becoming increasingly important. The serial assessment of ventricular function helps our understanding of the natural and unnatural history in these patients. Equilibrium radionuclide ventriculography is safe, easy to perform, and well-suited to the serial assessment of ventricular function. Fifteen nuclear studies were performed in 15 children with single ventricle complex. Nuclear studies were imaged in both the anterior and left anterior oblique views in each patient. The ventricular ejection fraction calculated from the anterior view (the view with the best atrial-ventricular separation) closely approximated the cineangiographic ejection fraction (54.0 vs 59.1%). Equilibrium radionuclide ventriculography is a valid method to calculate ventricular ejection fraction in single ventricle. The anterior view should be used for region of interest selection and subsequent ejection fraction analyses.