The clinical and instrumental characteristics of four patients suffering from idiopathic restrictive cardiomyopathy are analysed. Patients were diagnosed following hemodynamic and histological tests. The major clinical symptom was cardiac decompensation and/or hyperkinetic or hypokinetic (3rd degree BAV) supraventricular arrhythmia (atrial fibrillation). Electrocardiographic and radiological alterations were not specific. The most typical echocardiographic symptom was the association of: biatrial dilation, dilation and hypertrophy of the right ventricle, normal left ventricular size, normal fractional shortening of the left ventricle. Septal hypertrophy was also observed in one case. Abundant pericardial effusion was present in all cases. When performed, echo-Doppler showed a relatively typical shortened deceleration time through the A-V valve. Catheterism revealed increased ventricular telediastolic pressures and a bi-plateau morphology of the ventricular pressure curve. Heart index was depressed in one patient and the ejection fraction was reduced in one case. Histological tests revealed interstitial fibrosis, cellular hypertrophy and, in one patient, myocardial amyloidosis. One patient underwent a heart transplant, two patients died while waiting for a transplant, one patient is still alive 13 years after the start of 3rd class symptoms.