Echocardiography has evolved to be an important tool in the assessment of patients with hypertrophic and restrictive cardiomyopathy. In this article, the authors review the use of echocardiography in diagnosis, differentiation from disease mimics, assessment of prognosis, and the assistance of specific therapies. A pathophysiologic understanding of restrictive cardiomyopathy and constrictive pericarditis will be reviewed along with echocardiographic and Doppler features that help to distinguish these two entities.