Right ventricular (RV) failure after cardiac surgery is associated with an ominous prognosis. The etiology of RV failure is multifaceted and the ability to recognize RV failure early is paramount in order to initiate timely treatment. The present review focuses on different diagnostic modalities for RV function and discusses the normal versus abnormal findings in RV monitoring after cardiac surgery and the limitations of the applicable diagnostic modalities. There are specific challenges in RV assessment after cardiac surgery due to a loss of longitudinal contraction and a concomitant gain of transverse contraction. Additionally, the image quality of transthoracic echocardiography (TTE) is often reduced after cardiac surgery. RV function can be assessed with 2D and 3D imaging techniques as well as invasive hemodynamic monitoring. Until proper validation studies have determined accuracy, reproducibility and comparability of the next generation of diagnostic modalities we propose to use simple, but obtainable echocardiographic measurements and ultimately the insertion of a pulmonary artery catheter (PAC) in order to diagnose RV failure after cardiac surgery.