Tricuspid regurgitation and right ventricular dysfunction in patients with mitral valve disease is associated with poor outcome and predicts heart failure, and reduced functional capacity. Tissue Doppler imaging and myocardial performance index may provide good information about right ventricular function in patients undergoing mitral valve surgery. Our study aimed to identify variables which predict de novo/ continued right ventricular dysfunction following mitral valve surgery. Our study suggested that PASP is not a prerequisite for right ventricular dysfunction after mitral valve surgery.