Pulmonary hypertension is a common but underdiagnosed complication of systemic lupus erythematosus, which can be associated with significant morbidity and early mortality. Although often associated with anti-phospholipid antibodies, the etiology remains poorly understood. In case reports and small open trials, the anti-CD20, B-cell targeted therapeutic antibody, rituximab, has been reported to provide benefits for systemic lupus erythematosus patients with glomerulonephritis, anti-phospholipid antibody syndrome, vasculitis, arthritis, and refractory skin disease. However, the outcome of rituximab treatment of pulmonary arterial hypertension associated with systemic lupus erythematosus has not been described. We, therefore, present a case of a young systemic lupus erythematosus patient with early onset of pulmonary arterial hypertension during the disease course, refractory to multiple treatment modalities, who had significant improvement with rituximab therapy.