Objective. To investigate early cardiac involvement in patients with polymyositis/dermatomyositis (PM/DM), and to evaluate the risk factors for early cardiac impairment. Methods. The study population included 46 patients with PM/DM who did not have overt cardiovascular manifestations and 21 age- and sex-matched healthy controls. Traditional echocardiography and tissue Doppler imaging (TDI) were used to evaluate cardiac function in both groups. Clinical characteristics were recorded. Multivariate logistics regression analysis was applied to investigate risk factors for early cardiac impairment in patients with PM/DM. Results. No significant difference was found between patients and controls by traditional echocardiography. However, compared to controls, PM/DM patients had a significantly lower ratio of early diastolic mitral annulus velocity to late diastolic mitral annulus velocity (Em/Am; 1.23 +/- 0.52, 1.79 +/- 0.37, respectively; t = -4.485, p < 0.001) and a higher ratio of peak early diastolic transmitral flow velocity to Em (E/Em; 8.26 +/- 2.57, 6.76 +/- 1.17; t = 3.287, p < 0.05) as found by TDI measurements. There was no significant difference between the TDI variables of patients with PM and DM. The multivariate regression analysis showed that female sex (OR 11.044, 95% CI 1.066-114.357, p = 0.044), late onset (OR 1.157, 95% CI 1.047-1.278, p = 0.004), and duration of disease (OR 1.060, 95% CI 1.008-1.115, p = 0.023) were risk factors for abnormal left ventricular filling pressures. Conclusion. TDI is useful for detecting early cardiac impairment in patients with PM/DM. Left ventricular diastolic dysfunction is an early feature of cardiac involvement. Female sex, late onset, and long course of disease are 3 independent risk factors for predicting left ventricular diastolic dysfunction in patients with PM/DM.