A patient with connective tissue disease presenting with both protein-losing enteropathy and pancreatic involvement is reported. A 52-year-old female was admitted because of mild epigastralgia, anasarca and ascites. Serum albumin, transferrin and zinc, showed low levels. An Upper G.I. series and endoscopy showed thickened folds of the duodenum and the jejunum. Biopsy specimens revealed lymphangiectasia in edematous villi. 99mTc-labeled human serum albumin scintigram showed abnormal radioactivity in the small intestine 90 minutes after intravenous injection, indicating protein-losing enteropathy. Hypoalbuminemia was ameliorated by glucocorticoid therapy, but recurred twice when glucocorticoid treatment was tapered. Hypoalbuminemia has not occurred since intestinal lymphangiectasia was improved with glucocorticoid treatment. Levels of elastase 1 and lipase were high in serum and ascites on admission. Endoscopic retrograde pancreatogram showed no abnormalities. Serum pancreatic enzymes were also ameliorated by glucocorticoid therapy, but slightly high levels continued for about one year and a half. This case might have been diagnosed as systemic lupus erythematosus although mixed connective tissue disease was also suspected. There are few reports of protein-losing enteropathy and pancreatic involvement associated with connective tissue diseases. Protein-losing enteropathy and pancreatic involvement were ameliorated with glucocorticoid treatment, suggesting participation of immunological mechanisms.