The authors report a case of sarcoidosis associated with protein losing enteropathy. The diagnosis of intrathoracic stage I sarcoidosis was based on x-ray and biopsy of mediastinal lymph nodes. Enteric protein loss was suspected because of edema lasting for 2 yr, hypoproteinemia, decreased concentrations of serum immunoglobulins, and lymphopenia involving mainly T-cells and proved by 51CrCl3 test (21%/120 hr). Lymphography was consistent with granulomatous involvement of retroperitoneal lymph glands while small bowel biopsy showed blunt villi and dilated lacteals. All the pathological parameters normalized after 6 mo of prednisone treatment. In some cases of sarcoidosis, when abdominal lymph glands are involved, cellular and humoral immunologic derangements may be caused or potentiated by excessive enteric protein and lymphocyte loss.