Thirty one cases of congestive cardiomyopathy previously diagnosed as "idiopathic" were retrospectively studied in order to determine the prevalence of the following pathologic myocardial factors (MFs): severe alcoholism (A), systemic arterial hypertension (SAH) and obstructive coronariopathy (OC). Sixteen (51%), 14(45%) and 9(29%) cases had an association with A, SAH and OC, respectively. Any of these MFs was present in 48% of cases, 2 of them in 19% and 3 in 13% of cases. Some peculiarities of the clinical findings, a particular interpretation of such findings by the attending physician and a modification of the psychological status of some patients were the main causes which prevented the recognition of these MFs. Besides, 67% of the cases had at least one of the following "minor" factors which contributed to the myocardial damage: mitral insufficiency, pulmonary embolism, atrial-ventricular block and diabetes mellitus. A careful investigation of these MFs should be done before a diagnosis of idiopathic congestive cardiomyopathy is considered. In some cases there is more than one pathogenic factor.