Pulmonary hypertension (PH) is a rare but potentially life-threatening complication of systemic lupus erythematosus (SLE). We reviewed the literature on this complication, its pathogenesis and clinical presentation, and treatment options. PH is reported in 0.5% to 14% of patients with SLE. The literature describes the cases of 105 patients, 90% of whom were female. Average age was 33 years, and overall mortality was 25 to 50% two years after PH diagnosis. As in patients with primary pulmonary hypertension, dyspnea is the most common presenting symptom of PH in patients with SLE. Up to 58% of patients with both PH and SLE have Raynaud's phenomenon. Echocardiography can show right ventricular hypertrophy and dilation, even before symptom onset. Right-heart catheterization, with an assessment of vasoreactivity, is a necessary part of the work-up and is also needed for treatment decision-making. PH in patients with SLE is associated with intimal hyperplasia, smooth-muscle hypertrophy and medial thickening, similar to the changes seen in primary PH. Several pathological mechanisms have been proposed for PH associated with SLE. They include vasoconstriction, vasculitis, thrombosis, anticardiolipin antibody and lupus anticoagulant. Endothelial dysfunction may be an important factor in the onset of PH, possibly by contributing to vasospasm. Higher serum endothelin levels are found in patients with SLE and pulmonary hypertension than in other SLE patients. Several specific antibody patterns have been reported in patients with PH and SLE. Oral calcium channel blockers are indicated for patients who respond to acute NO challenge. Continuous intravenous prostacyclin represents a therapeutic advance, although it appears less effective than in primary PH. Some patients have been improved by new oral endothelin receptor antagonists, usually combined with intensive immunosuppressive therapy. Patients with SLE have an increased risk of PH. Vigilance is therefore required to detect early signs of PH. Early diagnosis allows treatment to start before irreversible vascular lesions occur.