Echocardiography is one of the most frequently used techniques for diagnosing cardiovascular diseases. The Echocardiography Lab. is one of the major units of the Diagnostic U/S Centre at Cairo University Hospitals where patients admitted to Cairo University Hospitals as well as patients from outpatient clinics were referred for Echocardiographic diagnosis. Database analysis of more than 22000 echocardiographic examinations at the echocardiography Lab. was performed to study the detailed anatomic & functional description of most common cardiac diseases. Statistical analysis was also done to study the prevalence of different cardiac diseases & the change of pattern of different cardiac diseases over the last decade with focusing on rheumatic heart disease and the valves affected by rheumatic heart disease.