We report a systemic lupus erythematosus patient with lupus anticoagulant accompanied by pulmonary thromboembolic hypertension possibly due to large vegetation of the tricuspid valve of the heart. Histopathological analysis of localization and distribution of thromboemboli in pulmonary vasculature revealed that the organized thromboembolic occlusion of multiple blood vessels (99 out of 222 arteries), might be responsible for the pulmonary hypertension both in quality and quantity. The contribution of lupus anticoagulant to the pathogenesis of Libman-Sacks endocarditis in systemic lupus erythematosus, and its possible relationship to pulmonary thromboembolic hypertension are discussed.