Real-time three-dimensional (3D) echocardiography allows us to measure right ventricular (RV) end-diastolic volume irrespective of its shape. Tissue Doppler imaging (TDI) and speckle tracking imaging (STI) are new tools to assess myocardial function. We sought to evaluate RV function by 3D echocardiography and myocardial strain imaging in adult patients with atrial septal defect (ASD) before and 6 months after transcatheter closure in order to assess the utility of these new indexes in comparison with standard two-dimensional (2D) and Doppler parameters. Thirty-nine ASD patients and 39 healthy age- and sex-matched controls were studied using a commercially available cardiovascular ultrasound system. 2D-Doppler parameters of RV function (fractional area change, tricuspid annular plane systolic excursion, myocardial performance index) were calculated. 3D RV volumes were also obtained. RV peak-systolic velocities, peak-systolic strain, and peak systolic and diastolic strain-rate were measured in the basal, mid and apical segments of lateral and septal walls in apical 4-chamber view by TDI and STI. In open ASD, RV ejection fraction (3D-RVEF) and global and regional RV longitudinal strain were significantly higher than control group and decreased significantly after closure. By multivariate analysis 3D-RVEF, apical strain and strain rate were independent predictors of functional class. ROC analysis showed 3D-RVEF and apical strain to be more sensitive predictors of unfavorable outcome after defect closure compared to 2D-Doppler indexes. 3D echocardiography and myocardial strain imaging give useful insights in the quantitative assessment of RV function in ASD patients before and after closure.