A 43-year-old woman was diagnosed with pulmonary hypertension (PH) associated with systemic sclerosis (SSc). On admission, absence of both thromboembolism and severe interstitial lung disease suggested that vascular damage led to PH. In addition, the patient met the criteria for the classification of SLE. Methylprednisolone pulse therapy was effective not only for the clinical symptoms but also the laboratory findings. The report of overlap syndrome associated with PH is rare. The prognosis of patients with collagen diseases associated PH has been reported to be extremely poor. Since PH in this case responded favorably to methylprednisolone pulse therapy, this therapy may be effective for PH associated with overlap syndrome.