Structural, architectural, contractile or electrophysiological alterations may occur in the left atrium (LA). The concept of LA cardiopathy is supported by accumulating scientific evidence demonstrating that LA remodeling has become a cornerstone diagnostic and prognostic marker. The structure and the function of LA and left atrial appendage (LAA) which is an integral part of the LA, are key elements for a better understanding of multiple clinical conditions, most notably atrial fibrillation (AF), cardioembolism, heart failure and mitral valve diseases. Rational use of various imaging modalities is key to obtain the relevant clinical information. Accordingly, this clinical consensus document from the European Association of Cardiovascular Imaging, in collaboration with the European Heart Rhythm Association, provides comprehensive, up-to-date, and evidence-based guidance to cardiologists and cardiac imagers for the best practice of imaging LA and LAA for the diagnosis, management and prognostication of the patients.