It is not clear how frequently hypertrophic cardiomyopathy coexists with essential hypertension or whether chronic hypertension per se, induces hypertrophic cardiomyopathy (hypertensive hypertrophic cardiomyopathy). Eighty-three Nigerians with essential hypertension alone underwent M-mode and 2 dimensional echocardiographic study. Twenty per cent (17 patients) had disproportionate intraventricular septal hypertrophy (septum: posterior wall ratio > or = 1.4). These subgroup tended to be elderly, with average age of 57.7 years, and were predominantly male (70%). Two patients in this subgroup (2.4% of total) additionally had thickened posterior left ventricles and a hyperdynamic left ventricular systolic function (fractional fibre shortening of > or = 45%). This picture is consistent with "hypertensive hypertrophic cardiomyopathy". Routine echocardiography may permit the early identification and thus a closer scrutiny and follow up of essential hypertensive patients with disproportionate septal thickness. The prognostic implications of this requires long term study.