Four Black South African patients, representative of a larger group, are described in detail. The common features were long periods of observation, multiple hospital admissions in both normotensive and hypertensive cardiac failure, hypertensive retinopathy and good renal function. All had been diagnosed as having cardiomyopathy. Two of the patients in a normotensive phase became hypertensive after responding to therapy for heart failure. One patient with malignant hypertension showed the features of idiopathic cardiomyopathy at necropsy. These cases are regarded as evidence in favour of the hypothesis that many cases of cryptogenic heart disease (cardiomyopathy, congestive cardiomyopathy, idiopathic cardiomegaly) are in fact cases of hypertension presenting with normotensive cardiac failure.