In Arterial hypertension abnormalities of left ventricular filling are constant and appear at an early stage, and in most cases signs of left ventricular failure (LVF) precede alterations in the left ventricular systolic function. The purpose of this study was to evaluate the frequency as well as the clinical and echocardiographic characteristics of LVF with normal systolic function in permanent arterial hypertension. 113 permanently hypertensive patients with normal left ventricular performance at echocardiography were studied clinically (functional class, congestive signs of LVF and/or presystolic gallop) and by means of echocardiographic recordings (dimensions of the left ventricle, mitral EF slope, left atrial diameter). The left ventricular wall thickness was normal (less than or equal to 11 mm) in 31 patients (group I), increased with asymmetrical septal hypertrophy in 36 patients (group II) and diffusely and symmetrically increased in 46 patients (group III). The EF slope was significantly smaller and left atrial dilatation was significantly more frequent in groups II and III than in group I. Clinical signs of LIF and presystolic gallop were observed in only groups II and III. Clinical LVF was found in 33/113 hypertensive patients (29%) and was always accompanied by symmetrical or asymmetrical left ventricular mural hypertrophy. Moreover, presystolic gallop (n = 8, i.e. 24%) and left atrial dilatation were significantly more frequent in patients with LVF than in those without LVF. Thus, LVF with normal systolic function is frequent in permanent hypertension. It results exclusively from abnormalities of left ventricular relaxation and/or compliance.