The right ventricle (RV) is of lesser importance in acquired heart disease, but its role is of increasing importance in congenital heart disease (CHD). Despite major progress being made, precise measurements of the RV are challenging because of its peculiar anatomical structure that is not adaptable to any planar geometrical assumption. This is particularly true in adult patients with CHD where the RV shape eludes any standardization, it may assume various morphologies, and its modality of contraction depends on previous surgical treatment and/or pathophysiological conditions. However, reliable and repeatable quantification of RV dimensions and function for these patients are essential to provide appropriate timing for intervention to optimize outcomes. In this population, echocardiographic evaluation should not be limited to an observational and subjective functional assessment of the RV but must provide quantitative values repeatable and clinically reliable to help the decision-making process. The aim of this review was to discuss the echocardiographic approach to the RV in adult patients with CHD in general and in specific cases of pressure or volume overload.