A 64-year-old woman was hospitalized because of poor general condition, gastrointestinal upset, unexplained fever, electrolyte imbalances, and an incidental finding of bilateral huge adrenal masses on computerized tomography (CT) of the abdomen. Non-Hodgkin's lymphoma (NHL) of B-cell origin was proven by ultrasound-guided aspiration biopsy of the left adrenal gland. Meanwhile, primary adrenal insufficiency was confirmed by her low serum cortisol level, high ACTH level, and inadequate adrenal response to the rapid ACTH stimulation test. The diagnosis of primary adrenal NHL was supported by detailed physical examinations, bone marrow examination, and such imaging studies as CT scan and sonography. She received three courses of chemotherapy with cyclophosphamide, vincristine, and prednisolone and there was an initial transient response, but she died of sepsis and progression of NHL three and a half months later.