This book begins with the fundamentals of echocardiography describing historical background of ultrasound, instrumentation, various modes in practice, examination of normal cardiac structures with M-mode, 2-D, Doppler and colour flows. This chapter is considered as the sheet anchor of basic clinical echocardiography, most useful to cardiac fellows and technical officers of cardiovascular medicine. As it proceeds further, it highlights the importance of M-mode, 2-D and colour Doppler echocardiography in the assessment of rheumatic and congenital cardiac defects which is the main bulk load of any diagnostic echocardiographic laboratory in South East Asia including India. Newer concepts of differential blood supply of IVS has been highlighted to prove that there exist two parts of IVS with different coronary arterial supply with central demarcating line. Echocardiographic evaluation of intracardiac mass lesions, pericardial diseases, A-V prolapse, infective endocarditis and right heart dysfunctions secondary to cardiorespiratory disorders have been lucidly depicted.