Purpose: Clinically significant valvular heart disease due to systemic lupus erythematosus (SLE) has generally been considered rare, and Libman-Sacks endocarditis has been thought to be predominantly an autopsy finding. With the declining prevalence of rheumatic heart disease, however, the spectrum of valvular heart disease is changing. We retrospectively analyzed our experience with SLE between 1975 and 1987 for the presence of hemodynamically significant valvular heart disease. Patients and methods: An existing data base of 421 patients with SLE was selected for review. Patients were selected for inclusion in the study if they met four or more of the criteria of the American Rheumatism Association for SLE, they had clinically significant valvular heart disease, and tissue from the involved valve was available for review. The etiology of the valve lesion was determined by assessment of the clinical history, chart review, gross morphology, and valve histology. Results: Of 14 cases with pathologic material available for review, six had anatomic features of SLE valvular heart disease such as verrucous vegetations or valvulitis with necrosis and vasculitis. Two of these patients underwent successful valve replacements and four died from complications of their valve disease. Conclusion: We suggest that significant morbidity and mortality may result from SLE valvular heart disease in about 1 to 2 percent of SLE patients and that the pathogenetic mechanisms underlying valve dysfunction in SLE patients are multifactorial. © 1988 Mead Johnson & Company, Evansville, Indiana, 47721, U.S.A.