Scleroderma affects the left heart directly and indirectly via the effects of systemic hypertension. Using transthoracic echocardiography, we evaluated 35 patients with scleroderma and compared them with matched control subjects. Compared with controls, there were no differences between left ventricular dimensions, wall thickness, calculated mass or fractional shortening. However, the left atrium was enlarged (P = 0.006) and the mitral deceleration time was prolonged (P = 0.0005) in patients with scleroderma; suggesting abnormal diastolic function. After adjusting for potential confounders, duration of Raynaud's was found to be an independent predictor of deceleration time (P = 0.04), E/A peak velocity ratio (P = 0.04), A peak velocity (P = 0.004) and A velocity time integral (P = 0.0001), all measures of diastolic function. This group of individuals with scleroderma have evidence of abnormal diastolic function of the left ventricle despite normal left ventricular size and systolic function, and in the absence of hypertrophy. This finding is independent of the use of vasoactive medications and history of systemic hypertension, and thus may be due to primary myocardial involvement by scleroderma. The tendency to abnormal diastolic function of the left ventricle correlated with the duration of Raynaud's phenomenon.