After a short description of the physical principles of ultrasound, the indications and usefulness of the real time B-scan technique in the non-invasive diagnosis of cardiac and abdominal diseases are discussed. A correct diagnosis was made in 90% of the cardiac cases (valve abnormalities, pericardial effusion, cardiac aneurysm, cardiomyopathy), whereas the diagnosis by ultrasound was correct in only 81.1% of the abdominal cases (diffuse and localized liver diseases, pancreatitis, pancreatic cyst, carcinoma of the pancreas, cholelithiasis, renal cyst, renal tumours, aortic aneurysm). The advantages of the real time B-scan technique lie in the two-dimenstional clear representation of intracardiac and intraabdominal structures with the possibility of undertaking quantitative measurements. Furthermore, it is a non-invasive and safe method, which can be repeated as often as necessary and can complete the diagnositic spectrum of radiology, endoscopy and nuclear medicine.