A major burning issue in children, adolescents and young adults in developing countries like India are acute rheumatic fever (ARF) and its long-term sequel chronic rheumatic heart disease (RHD). In 39% of ARF patients, varying degrees of pancarditis with associated valve insufficiency, heart failure, pericarditis and even death may occur. Two-dimensional (2D) transthoracic echocardiography (TTE) is a noninvasive, essential key tool for the diagnosis and evaluation of carditis in ARF. The etiology, severity, hemodynamic consequences and ventricular response to valvular abnormalities can be assessed with appropriate echocardiographic techniques. This chapter covers the jones criteria, echocardiography versus clinical examination, application of Vijaya’s echo criteria, rheumatic versus nonrheumatic regurgitation, physiological versus pathological regurgitation, and application of revised jones criteria 2015. It is a historic revision of the Jones criteria for the sixth time in 2015. The diagnosis of carditis, which is a major manifestation of ARF, is mainly by Doppler echocardiography.