We report a case of primary adrenal NHL associated with adrenal insufficiency which was successfully treated with steroid replacement and chemotherapy. A 69-year-old woman hospitalized with fatigue and weight loss developed shock and recovered with steroid therapy. Adrenal insufficiency was confirmed by an elevated plasma adrenocorticotropic hormone level and low cortisol. Computed tomography revealed large bilateral adrenal masses. Needle biopsy showed a diffuse, mixed B cell lymphoma. CHOP therapy accompanied by steroid replacement was begun, and she achieved a complete remission after 4 cycles. She received additional 4 cycles of chemotherapy. Although adrenal insufficiency was irreversible, she has continued in complete remission for 50 months at this reporting.