A 54-year-old female experienced morning stiffness and arthralgia of the hands from November 2001 and consulted her local doctor in January 2002. Hematological data showed liver dysfunction and antinuclear antibody was positive. In February 2002, the patient was admitted to our hospital to investigate these abnormalities of liver function further. The features of arthritis, thrombocytopenia with elevated platelet-associated IgG, positive antinuclear antibody, and anti-DNA antibody lead to a diagnosis of systemic lupus erythematosus. Liver biopsy revealed infiltration of Glisson's capsule by plasma cells, compatible with autoimmune hepatitis. We performed hepatic venography to investigate severe pancytopenia, remarkable splenomegaly and esophageal varices. Wedged hepatic venous pressure was mildly elevated, and hepatic veins displayed sharp angles, smooth walls and development of anastomosis with each other. These findings suggested idiopathic portal hypertension. Cytopenia and liver dysfunction gradually improved on treatment with 40 mg/day prednisolone. Esophageal varices were disappeared, and splenomegaly had improved after 6 months. As autoimmune factors are considered to underlie the development of idiopathic portal hypertension with systemic lupus erythematosus, steroid administration represents a therapeutic option in this condition.