Thirty-five consecutive patients with systemic lupus erythematosus were enrolled in a prospective study. Investigations included a physical evaluation, tests for antinuclear antibodies and antiphospholipid antibodies, an electrocardiogram, a plain chest film, a 2D echocardiogram and a Doppler study. Clinical cardiac manifestations and alterations of the electrocardiogram were infrequent (17% and 11% of patients, respectively) and no patients had abnormal chest film findings. In contrast, echocardiographic abnormalities were common (82% of patients), although moderate in most instances. Pericardial involvement was found in 15 patients (42.8%); a pericardial effusion was seen in 9 of the 14 patients with inactive disease (p < 0.003), whereas thickening of the pericardium was visible in 4 patients with active disease and 2 of the 21 patients with inactive disease. Valve abnormalities were found in 17 patients (48.5%), but were not related to the presence of antiphospholipid antibodies; valve alterations included verrucous endocarditis in one case, valve thickening in one case, mitral prolapse in five cases, and mild or moderate regurgitation in 15 cases (aortic in 2 cases, mitral in 7 cases, pulmonary in 3 cases and tricuspid in 7 cases). Alterations in ventricular chamber size and kinetics were also fairly common, albeit of uncertain pathogenetic significance. These data confirm the value of 2D echocardiography for identifying and monitoring cardiac involvement in systemic lupus erythematosus, even in patients with no overt clinical manifestations.