Amyloidosis with extensive cardiovascular involvement was seen in five patients. Each exhibited the following clinical pictures: intractable congestive heart failure, ischemic heart disease, pericarditis with effusion, valvular heart disease, and orthostatic hypotension. The electrocardiographic findings of low voltage, left axis deviation, and absent or poor progression of the R waves in the extremity or precordial leads, although not specific, should alert the clinician to the possibility of cardiac amyloidosis. The typical low voltage may be concealed by the development of aberrant ventricular conduction or bundle-branch block.