A 65 years old male, who had complained of severe lower back pain with generalized muscular weakness, nausea and constipation since last 18 months, showed typical loboratory and radilogical findings of primary hyperparathyroidism. It had extensive skeletal involvement and some urological complication. The mass, which was palpated in the right upper corner of the thyroid, was surgically completely removed. It was measured 8×4×3 cm, and was weighed 38 gm. Microscopic examination revealed adenoma of the parathyroid gland consisting of small dark chiefe ells. Postoperative course has been satisfactory. (